Hi!
I disagree with moonie. If that's the way you want to go, PHP is something you may start with. It is not that difficult (and you don't really have to know much of HTML, anyway, so I beg to differ on this point). PHP has loose typing (meaning variables don't have to be declared as a specific type before usage), it has so many functions for use that if you ever convert even to such a 'basic' language as Visual Basic, you will regret it. It looks like 5-6 years of development of PHP have done to it much more than about 10-15 years of development of Visual Basic by such a software giant as Microsoft!
PHP is easy. You need to get a few things: how operators, loops, etc. work, you need to think about your coding style and polish it over the years, develop your software better, but other than that, you don't need to know anything. Actually, even very good developers don't know all of the basic functions' syntax. Most of the time they just have the PHP help close by.
If you are able to figure out how a telephone or TV works (and, what is more important, if you enjoy learning about such things), you do have a future as a developer. If you are going to do it for fun, I guess it's better to go out and have fun outside instead of hunching your back over the computer screen.
Best,
Stas