Creating A Simple Test Server?

So, I wanna learn PHP. I already know HTML and CSS(been awhile though ). I want to start learning JavaScript and PHP along with MySQL. However, I don't gots me money! So obviously doing anything like paying for hosting is out of the question. And to learn, people don't even need to see what I'm doing, so I thought, Couldn't I just run a server on my computer that's only in my local area network? Would anyone know about how to do that? Would it be as simple as getting the server software that runs PHP and then sending it an IP to fetch a document?

For the fun of it, also, how hard would it be to get it semi-public, as in I could send my friends my IP but not have search engines picking it up(because it's not on a DNS or whatever).

I hope I said this all right! (Btw: I have "experience" with port forwarding and all. I understand basic networking, which has all stemmed from research after learning to run a Minecraft Server.)

Yep, you can set up your own web server at home. Indeed, I could run YWS from my home computer if I wanted to (although I wouldn't be able to do anything else on it, and YWS would go dark whenever I turned off my computer).

The best way to go about doing this is setting up a LAMP server. LAMP stands for Linux-Apache-MySQL-PHP. Those are the four technologies that together pretty much make up every single website you visit.

The hardest part, though, of setting up a LAMP server is the L part. Once you have Linux running on your computer, the rest is really easy. You can find instructions for setting up the AMP part here:
http://www.howtoforge.com/ubuntu_lamp_for_newbies

For the L part, I recommend Ubuntu and VirtualBox. VirtualBox is an application that runs in Windows or OS X, and through which you can boot a separate operating system. It's really cool because you can run Linux almost like a different application on your computer. To install VirtualBox, go here:
http://www.virtualbox.org/wiki/Downloads

For instructions on installing Ubuntu using VirtualBox, go here:
http://www.psychocats.net/ubuntu/virtualbox

Now, all this is pretty difficult stuff. So if you have any questions, feel free to ask. Alternatively, you can set up a WAMP service (W is for Windows). I've never done it, but there are instructions here:
http://teamtutorials.com/web-developmen ... amp-server

What about Ubuntu's Wubi installer(Have you ever heard of it? I think it's fairly new, and if your like me, once I have something, you don't bother reading up on it anymore )? I've looked a little into that, but all that stuff scares me because it has to probably be changing the startup(What's it called BIOS?)