Basic Question: Where Do I Type All This In?

Perhaps I am missing something. Where do I actually go to type in all this HTML/coding to set up a web site?

In a .html file which you can create with a text-editor (notepad++ for example), then you just need to find a server (github pages for example) where you can upload the files, and then you have your website. If you need more details, let me know

hai will you tell me more about it