Welcome to this in-depth guide on building a basic React app on MacOS. In this first chapter, we'll set up the necessary tools and get our development environment ready.

First, we need to install Node.js and npm. Node.js is a JavaScript runtime that allows you to run JavaScript outside of a browser, and npm, the Node Package Manager, is used to install libraries like React.js.

To verify your installation, open your terminal and run 'node -v' to check the Node.js version.

And then run 'npm -v' to check the npm version.

Now that we have our environment set up, let's create our React project.

Run 'npx create-react-app my-react-app' in your terminal to create a new React project named 'my-react-app'. This command uses 'npx' to ensure the latest version of 'create-react-app' is used.

Then, navigate into the newly created project directory by running 'cd my-react-app'.

Finally, let's run our React app and see it in action.

Run 'npm start' to start the development server. This will launch the app in your default browser at 'localhost:3000'.

And there you have it! Your basic React app is up and running. You can now start building your own components and features.