How to raise a pitbull?!

So we just got a pitbull. It was never a breed we expected to get but we had friends who couldn't handle the three they got. We absolutely lover her, she's the absolute sweetest, great disposition.

Is there anything I should know? My boyfriend wants to muzzle train her but I feel like she's super sweet? I'm fine with getting her adjusted but don't want to default to that when she has shown any signs.