To begin, you need to click on get started, and a window will appear with documentation on it which is pretty nice as it will show you the basics of creating a simple chart. When you click on installation, and it will show you all the different methods you can use for example you can install using NPM if you want you can install using node js or Bower which is a frontend package manager.
Still, we are going to go for the simple route and use CDN which just a remote link to the chart.js file and also you can download and include it in your local structure as well. You will need a text editor for the next step, let us say you use Atom, you will have to create a new work filed by clicking on a new project folder, after creating a new folder you will have to create a new index HTML file here and add some basic HTML tags.
Add a suitable title to your file and put in your script tags as you will need to bring in the CDN. Next, you have to bring in the source, and you can opt for getting the minified version and paste that in, you can also grab the bootstrap just in case you want to enhance styles later. Once this setup id ready you can go to the body and create a div with the class of a container, and you will need an element to insert a chart, preferably the canvas element which is an HTML5 functional element.