What level is that?
PG 100 of this thread has all your answers.
level 14.
What is the best mode to play in to level up?
SnD can give a lot of points if you are getting kills... sucks is you're not though.
TDM becomes tedious after a while.
HQ can give quite a few if you defend a lot.
CTF is not bad just don't kill a flag holder (like -1500 points)
My favorite is DEM though.