Since the balancing question has been addressed, let me mention some other possibilities that might cause hum & noise.
Having had experience running sound I'd like to throw a few suggestions out. You may already know this but here goes anyway.
Make sure all grounds are grounded, including mics. Using 57's & 58's? Conversely, make sure things that aren't supposed to be grounded aren't, like those 1/4" jacks. For instance, the little plastic insulator has a way of disappearing.
Same goes for all the cables & the snake. Additionally, only use shielded for shielded applications, etc.
Make sure power is in phase. This will help the most when you plug in, as over half the places you'll set-up in will have screwed up AC. If your stuff is oriented correctly, easier to adjust. You probably don't have to now but learn how to get power from panels. Bad AC, dimmer switches & fluorescent lights are the PA's biggest enemy.
Having had experience running sound I'd like to throw a few suggestions out. You may already know this but here goes anyway.
Make sure all grounds are grounded, including mics. Using 57's & 58's? Conversely, make sure things that aren't supposed to be grounded aren't, like those 1/4" jacks. For instance, the little plastic insulator has a way of disappearing.
Same goes for all the cables & the snake. Additionally, only use shielded for shielded applications, etc.
Make sure power is in phase. This will help the most when you plug in, as over half the places you'll set-up in will have screwed up AC. If your stuff is oriented correctly, easier to adjust. You probably don't have to now but learn how to get power from panels. Bad AC, dimmer switches & fluorescent lights are the PA's biggest enemy.