Re: New Guy
What I would recommend, coming into role-playing as a total newbie, would be to find a game--any game, freeform or D&D or something else--with a setting that sounds interesting to you. Contact the GM of that game and ask to be added to the game as a lurker. That gives you access to read everything in the game (you can't post anything, except in private messages to the GM), and you can 'follow along' for a while to see what people are doing and how they're doing it.
Unless, of course, you're okay with the 'jump in on the deep end' approach, in which case I'd say find an interesting game and just ask to join the game, and explain to the GM (and the other players, if accepted) that you're totally new and need some coaching.
There's only so much we can tell you here to help get you 'up to speed', because there's a huge variety of games out there and even within games of the same type, there's a lot of variation in how the GM will run them, specifically. In general, yes, the games mostly run the same, but just about every GM has their own specific tweaks to how games run.