Originally Posted by LordDurham
Is it normal I managed to unlock The Challenger and Not Some Recruit Anymore even though I didn't play any multiplayer games yet? I only completed campaign on heroic and two on legendary all by mysef. I do was log on xbox live though. I don't know how the multiplayer system works yet, my guess is you still get points from campaign, but it doesn't seems like according to your guide.
If you played the Campaign missions Dawn on Legendary difficulty you completed one of the Weekly Challenges for Campaign. This would have gotten you 4750 XP, which is enough to get to level 5. So, yes, it's normal that you got The Challenged and Not Some Recruit Anymore by playing solo Campaign. Other than from challenges though, you do not get XP from playing Campaign, either solo or co-op.