To use Node.js in a project, you will first need to install Node.js on your computer. You can download the installer for your operating system from the official Node.js website (https://nodejs.org/en/download/). Once Node.js is installed, you can use it to run JavaScript code outside of a web browser.

Here is an example of a simple Node.js script that logs "Hello, World!" to the console:

console.log("Hello, World!");

You can run this script by saving it to a file with a .js extension, such as hello.js, and then running it from the command line with the node command:

node hello.js

This will output "Hello, World!" to the console.

To use Node.js in a larger project, you will typically organize your code into modules, and use require and exports to include and share code between files.

For example, you can create a file add.js that exports a function:

//add.js
const add = (a, b) => a + b;
module.exports = add;

And then you can include that module in another file and use the exported function

//app.js
const add = require('./add');
console.log(add(1,2)) //3

You can run it via command line as well

node app.js

This is just a very very very basic example of how to use Node.js in a project, but it should give you an idea of how to get started. As your project grows in complexity, you may want to use a framework such as Express.js to help organize your code, or a package manager such as npm or yarn to manage dependencies.

Best of luck!!