Play search and destroy, if your a good at the game that is. you can get about 10000 xp for one 6 minute game. if your are not the seasoned black ops player you should play headquarters you can get almost 20000 xp a game but the games are longer. hope this helps
In Black Ops multiplayer you unlock the AK-47 at level 38.
U can either came the whole game. Or if u have black ops or mw3 get double xp
You unlock gold camo in black ops, when you reach prestige level 14, level 25.
You have to be a level 26.
level 100
you unlock more emblems
Level 14
Level 35
15 pristige level 50
20000 xp a game in head quarters search and destroy 10-15000 xp a game 6 minute game
To level up in black ops you must get kills and earn experience just like anyother call of duty games.
In Black Ops, you don't get an offline multiplayer account. It only shows your playercard from your online account. So the answer to your question is; you can't level up on your Black Ops splitscreen account because you don't get splitscreen accounts in Black Ops.