A Guide for Getting Started with Claude Code and Codex for Nontechnical People
I've been using these tools every day for a few months. Recently, I moved many of my ChatGPT and Claude projects into local files so that Claude Code and Codex can run them directly. They're not just chatbots, but they can be used as chatbots. They can also run your computer and actually do things, like creating files, designing websites, organizing data, and writing code.
This is the closest thing to an AI coworker I've used and it's the easiest way to experiment with early agents, because Claude Code and Codex are the best agents currently available.
This is a guide for the people who get a little nervous when they need to open Terminal (or don't know what it is). I'll try to break down the complexity, simplify the buzzwords, and allow you to build something quite incredible within the next hour.
What these tools are
Claude Code, Codex, and Gemini CLI are AI tools that run on your machine and connect to models over the internet. They are command line tools, which means they run in the Terminal, that black screen with the blinking cursor that developers use. It's how software gets built, servers get managed, and systems get configured. When you add these AI tools to the Terminal, you can just type what you want in plain words and they make it happen. If you're thinking about JARVIS right now you aren't far off. Where ChatGPT, Claude, Gemini, and (especially) Copilot can sometimes fall on their face when doing real work, these tools can often get the full job done.
They can make a spreadsheet accurately from a messy text file. They can build a website or application end-to-end in minutes. In short, you just tell them what you want and they write the code, create the files, and put everything where it needs to go.
They all work similarly, so pick one based on what you currently pay for, as ChatGPT/Claude/Gemini subscriptions come with usage for these tools:
- Claude Code: Made by Anthropic, this tool invented the category. Requires a Claude Pro ($20/month), Max ($100-200/month), or usage-based API billing. Claude Code can also be used through the Claude Desktop app, which has a dedicated Code tab that avoids the Terminal entirely.
- Codex: Made by OpenAI and quickly catching up to Claude Code. Requires ChatGPT Plus ($20/month), Pro ($200/month), Business, or usage-based API billing. They recently launched a Codex Mac app, making the tool much more accessible if you don't want to touch a Terminal. Over 1 million people downloaded it in the first week. It's a big deal.
- Gemini CLI: Made by Google. Unlike the others, it has a free tier if you log in with your Google account. Easiest starting point if you don't have a paid subscription elsewhere, but it's the least popular among the three.
You don't need all three. Pick one and we'll get started.
Setup
Pick one:
This is the simplest option and it's free to start.
That's it. The free tier gives you 60 requests per minute and 1,000 per day — plenty to get started.
What you'll see when you open them
These tools come in two flavors: a Terminal (text-based command line) and a desktop app.
If you're using a Terminal (Claude Code, Codex CLI, or Gemini CLI), you'll see a blinking cursor waiting for you to type something. Just type something in (or talk with Whisper Flow) and hit Enter. You'll see the tool start to think, then start doing things, often reading files, writing code, or creating folders. By default, it'll ask for your permission before taking actions on your machine, which is an important safety net. Pay attention to what it's doing. Type y to approve or n to deny. That's basically it. You talk to it like a coworker and it does work for you.
Claude Code has a few extras hiding that are worth talking about. Type / and you'll see a menu of commands, including plugins, skills, and other shortcuts that extend what it can do. You don't need any of that to get started, but it's there when you're ready to go deeper.
If you're using the Codex Mac app, you'll see something that feels more like a project management tool. There's a sidebar on the left with your projects and threads (think: chat history), a prompt area at the bottom where you type what you want, and a main workspace where you see what the agent is doing. When it makes code changes, you get a visual diff (think: tracked changes in Word) where you can approve or reject each change. You can run multiple agents at once, each working on a different task in their own thread. It's a friendlier starting point if the Terminal makes you uncomfortable.
Both approaches do the same thing. Pick whatever feels right.
Three things to try
Okay, great. You're in. Welcome. Now, let's see what these powerful tools are capable of. I've put together three prompts that will open your mind to the opportunities, then you'll likely be addicted.
Turn messy data into a spreadsheet
You may love creating spreadsheets. I do not. But I love seeing data neatly organized in a spreadsheet. These tools make my life easy by handling all the work behind the scenes to get me the outcome I want without the headaches.
Let's assume you have a text file with a bunch of notes, or data copied from somewhere that needs to be organized. Grab those files. We'll simply drag them into the Terminal or Codex Mac app and enter a prompt like this:
I have a text file called "expenses.txt" in my Downloads folder. It has about 6 months of purchases, one per line, but the formatting is all over the place. Dates are written differently, some amounts have dollar signs and some don't, and store names are inconsistent. Create an Excel workbook with a clean transaction log on the first sheet: columns for Date (MM/DD/YYYY), Store (standardized names), Category (groceries, dining, gas, etc. — your best guess based on the store), and Amount (numbers only). On a second sheet, build a monthly summary with a pivot table showing total spend by category per month and a row of monthly totals at the bottom. Highlight any transaction over $200 in red. Save it to my Desktop.
Replace the file name, location, and column descriptions with your actual data. The tool will read the file, parse the mess, and create a spreadsheet you can open in Excel or Google Sheets.
That's a simple example. I'm not much of a spreadsheet power user, but if you are, these tools can speak your language. They can save you hours on advanced Excel tasks. For example, give it months of bank statements and ask it to categorize every transaction, build a monthly summary with pivot tables, calculate running averages, and flag anything that looks like a duplicate charge. It'll write the formulas, build the pivot tables, apply conditional formatting, and hand you a workbook. Without needing the aspirin or bourbon when you're done.
The real unlock with these tools is bringing your own expertise to them. A developer who can describe the exact tech stack, project structure, and UX patterns they want in a project will get a better outcome than someone who says "build me the best website ever." Same principle here. If you already think in spreadsheets, you can describe exactly what you need and these tools will handle execution. In many cases, the specificity of what you ask for is what separates a decent result from a great one.
Build a simple website
With tools like Replit and Lovable, many people are learning that it's quite easy to build quick prototypes. These tools take that concept forward. This is where developers actually work, and as OpenAI stated with the release of the new GPT-5.3 Codex model, these tools can now do nearly anything a human can do with a computer (yes, that sounds like hype but it's really not).
Let's say you're thinking through a new landing page or a custom experience for an upcoming trade show. You can just describe what you want and let the tool build the entire thing:
Create a one-page website for our company's booth at the Midwest Cool Businesses Expo. Company name is "Cool Midwest Business" and our tagline is "We make cool things simple." The page should have a hero section with the company name and tagline, a section with three service cards (Consulting, Development, and Training) that flip on hover to show a short description, a countdown timer to the event date (March 15, 2026), and a contact form at the bottom that collects name, email, and "What can we help you with?" Use a modern dark theme with blue accents. Save everything in a folder called "expo-site" on my desktop.
When it's done, open the index.html file in your browser. You'll have a working website. Then, you'll run into many headaches as you go from "this is neat" to "but how do I get this on the internet," which is the kind of problem agencies like Mostly Serious exist to solve. We're happy to help you go from vibe-coded direction to launched website. Just reach out.
Beyond what we typically think of websites to do, they are also powerful tools for information delivery. I rarely read RFPs, legal documents, or project specs as documents anymore. I use a custom skill in Claude Code to build an information delivery website that provides all the same information, and more, in a way I can better digest it, with visuals, charts and graphs, content intelligently grouped, and complex topics explained in ways I will better understand them. Because I run this through my assistant, it knows how I like to learn.
One example of this is our current search for a Director of Development and Director of Operations. As people apply, I put their information into the tool and have websites built for each candidate taking me through their work history, alignment with our needs, strengths and weaknesses, and a draft interview outline following our unique hiring process. This doesn't save me time, but it makes me better at my job.
Build a basic web game
I've built a lot of silly games. My current infatuation is a crossover of Cookie Clicker (a ridiculous game Spence plays) and Diablo II (the best game ever created). I made no plan for this game. I just told Codex to make it. Then, I used Claude Code (much better at design, in my experience) to improve the interface by rambling my feedback of v1 into it. Now, I have Codex make improvements while I sleep, review it again before I go to bed and provide another round of feedback, then have Codex work on it again while I sleep.
This probably isn't going to make you better at your job. But in order to understand the future of work, you have to understand the capabilities of these tools. And one way to do that is to have fun with them outside of your work. And this is fun.
Here's an idea, but I encourage you to get creative and weird with it:
Create a simple memory matching game. It should have a 4x4 grid of cards, each with an emoji on the back. When I click a card it flips over. If I click two cards and they match, they stay flipped. If they don't match, they flip back after a second. Track how many moves I've made and show "You win!" when all pairs are matched. Save it in a folder called "memory-game" on my desktop.
Open the HTML file and you've got a working game.
What you can do next
Okay, you've got the basics down and you're ready to start exploring the possibilities of these tools. There are infinite directions you can go from here. Here's what I'd recommend:
- Integrate with the tools you use every day, especially if you want to build your first assistant.
- Explore plugins and skills, steps toward creating agentic workflows using these tools.
- When thinking of use cases, try changing your mental model from these being AI tools to being junior level employees. What would you have this employee do for you? Ask it and see if it can.
This is also where most people need guidance, because the setup gets more complex and the possibilities get overwhelming. And there are real security concerns as you dig in. Take it slow. This is a marathon not a sprint and you just ran further than most people will right now.
This is the future. And now you have a glimpse into what it will look like. Eventually, more companies will build interfaces on top of this technology. Claude Cowork, another tab in Claude's Mac desktop app, is an example of a step in that direction. But those tools are currently buggy and feel like limited versions of what Claude Code, Codex, and the Gemini CLI deliver to users.
Going deeper
If you want to learn this with your team, we run workshops.
Vibe Coding Advanced covers exactly this, setting up Claude Code, Codex, and Gemini CLI. It's two days, hands-on, and you leave with a deployed application. We recommend completing Vibe Coding Basics first if you're brand new to AI-assisted building, to cover web-based tools like Replit and Lovable before you get into the terminal.
Resources
If you want to go further on your own, these are good starting points.
- Claude Code setup guide: Official docs for installing and configuring Claude Code
- Codex quickstart: OpenAI's getting started guide for the Codex CLI
- Introducing the Codex app: OpenAI's announcement with a walkthrough of the Mac app
- Gemini CLI on GitHub: Google's open source repo with setup instructions and examples
- AI Runs My Week: My article on building a personal AI assistant with these tools