Level 9

Total Experience Required 11,434 [confirmed]

Level 100 progress: 0.17%

This is roughly:
Killing 39 people in Warzone, or...
Killing 39 people in Execution, or...
Killing 33 people in Wingman, or...
Scoring 8,168 points in Guardian, or...
Scoring 24,857 points in Annex, or...
Scoring 15,045 points in Submission.

Horde (TU4)

Completing 58 waves on Casual, or...
Completing 39 waves on Normal, or...
Completing 29 waves on Hardcore, or...
Completing 23 waves on Insane.

Or a combination of the above. Have fun!