Level 8

Total Experience Required 9,486 [confirmed]

Level 100 progress: 0.14%

This is roughly:
Killing 32 people in Warzone, or...
Killing 33 people in Execution, or...
Killing 27 people in Wingman, or...
Scoring 6,776 points in Guardian, or...
Scoring 20,622 points in Annex, or...
Scoring 12,482 points in Submission.

Horde (TU4)

Completing 48 waves on Casual, or...
Completing 32 waves on Normal, or...
Completing 24 waves on Hardcore, or...
Completing 19 waves on Insane.

Or a combination of the above. Have fun!