I see the “recording concerts is a sin” crowd has come out already. Ignore them.

The concert is probably going to be low light, so the best way to get some good pictures anyway is to shoot in ProRAW(but stay away from 48 MP. The phone should automatically switch to 12MP in low light, but setting it manually will ensure this. 48MP would be higher resolution, but you don’t have the light to drive it.) Shooting in proRAW gives you more breathing room when editing, which can help low light pictures become great anyway. Your main sensor at regular 1x zoom is gonna give you the best images, but you can try the 3x, just know that you’ll have a harder time getting light into it. The .5x might do well too given the amount of light it can bring in. Stay far far away from that 2x option, it’ll not end well.

The #1 most important rule: enjoy the show first. Taking pictures and video is fun and a great way to keep the memory alive, but don’t stress yourself out over it. Have fun!