How much of the single player have you played?
Also, there are short solo tutorials for both the spy and the mercenary that you HAVE TO PLAY before you can join an online game. Be sure to do that before you want to play with live folks. They are real quick little sessions, with no enemies, that give you a cursory overview of the mechanics of the two characters you can play in multiplayer.
And please excuse me if you guys already know all this stuff.
