One thing you might want to do before you play the multiplayer game is change your ADS (aiming down the sights). The default has it so that if you aim, it stays in aim mode, which can actually suck. Better to change it so that you have to hold down the aim button (right mouse I think is default?) to aim so that you can hip fire whenever you need as well. Makes it easier. The game is more difficult at the lower levels. I don't think you get create a class until level 4, and you constantly unlock more perks, weapons, etc as you play.