Navigate to wherever you want to store the files for your website. I store all of my projects in one folder; something like 'Users/me/Documents/source/my-project-folder'.
VS Code is what's called an "integrated development environment" (IDE) and it's what you will be creating your website on. Think of it like Microsoft Word, but for writting code!
Install VS Code: https://code.visualstudio.com/download
Once you have VS Code installed click the extensions button on the left hand side, search for, and download the Live Server extension. This will help you look at your website before you publish it to the internet. It will turn your computer into your own little web server.
In VS Code go to click the foler icon in the top left and select 'open folder' then select your project folder to open it in VS Code. Then click the 'new folder' icon near your project folder and create a new folder called "src". In your "src" folder create a new file called "index.html".
Paste the following into your html file, and click the "Go Live" button on the bottom of your screen:
<h1>Hello World!</h1>