I'm 12, I've decided (at least for the moment) that I want to be a games designer, I already know html code and I was wondering what programs and codes I need to use and learn to make a game, I want it to be a MMORPG, a little like Runescape/World of warcraft. I've used Adobe Dreamweaver to make a website already and have designed it.

Extra; If the codes any different I was hoping to make it an in-browser game. So you dont have to download it. And I know I probably wont be able to make a game as advanced as W.O.W at the age of 12, but I want to put a plan together of what I need to do if you know what I mean?