First off i want to say that no real pro players from MLG or any other organized pro gaming groups would even consider Call of Duty and even more so Ghosts a game they would play. You will only find casual, wanna be or i think i am pro in public lobbies.
Most players that organize teams that go on to tournaments know each other from outside the franchise they are competing in. So the chances of you getting noticed by playing this crap of a game is 1 out of 1,000,000.
The best way to do good in this franchise or any other competitve online game is just to keep playing and trying to party up with those you think would benefit from playing together. I have many friends that i play with all the time. But when i know it is time to do some *work* and start stomping, Well i know who to invite and who not to.