I have no gigging experience, but I do have drinking experience! Something that everyone should remember in ALL situations involving drinking is that alcohol and adrenaline make for a wild combo. You might know your tolerance and how any certain number of drinks will effect you normally, but add a HUGE adrenaline surge of playing a live show with a band, especially while still being new to do so… would be very easy to find yourself sloppy when you were hoping to just calm the nerves a bit. Probably better to just avoid drinking before/ during gigs… especially at first.