Starting weapon on Team Slayer

Games Halo: The Master Chief Collection
1

I am new to any halo because I just got my first Xbox console (Xbox one) 2 days ago, I got Halo mcc and I have only done team slayer, I always start with this assult rifle that is impossible to get kills on and I see others with better weapons, how dou change ur weapon? Thanks

2

You can pick up weapons on the map like the BR.
Team BRs is the mode where you start with a BR and an assault rifle.