Answer 1

You can just make it on your own computer locally, use a basic text editor (like notepad, or notepad++). Save one file as .html and the other as .CSS
Ensure they are in the same directory (for now) and then open your html file with a browser. Voila, your work appears (make sure you reference your CSS stylesheet, this will be easy if they are in the same place). You can add JavaScript this way and generally anything you want.