In case the numerous output busses and connectors in your mixing console seem overwhelming and somewhat confusing as to which one to use and for what purpose, then this video should help you out.
Check out the additional videos mentioned in this video:
How to create monitor mixes using Auxes: https://youtu.be/je62sNNZGv0
How to use Groups in live sound: https://youtu.be/FOPwLkzJQLM