Level 11

Total Experience Required 15,932 [confirmed]

Level 100 progress: 0.23%

This is roughly:
Killing 54 people in Warzone, or...
Killing 55 people in Execution, or...
Killing 46 people in Wingman, or...
Scoring 11,380 points in Guardian, or...
Scoring 34,635 points in Annex, or...
Scoring 20,964 points in Submission.

Horde (TU4)

Completing 80 waves on Casual, or...
Completing 54 waves on Normal, or...
Completing 40 waves on Hardcore, or...
Completing 32 waves on Insane.

Or a combination of the above. Have fun!