I want to learn PHP, but I am pretty much computer illiterate. What steps do I take?

I used to know some very basic HTML from a class in high school (6 years ago). I’d like to practice that more and then move on to something like PHP (if there is a more plausible next step, ideas are welcome).

But I completely forget where to start! Do I just learn some code and type it into notepad? Then what do I do? How do I view the product of my coding after I’ve typed it? Do I have to register a domain? How do I get the code from notepad to the website? Do I even need a website to view it? I read something about setting up a “web server” but I don’t even know what that is! So what do I need to download, buy, or install? What websites provide the best tutorials?

As you can see, I’m seriously way behind on this stuff and would appreciate if anyone could help me get started. I really could use a step-by-step guide to slowly explain all of this to me as if I were an idiot. Thanks a lot.