Mixing can learned along the way, reading the crowd and playing a wide variety of music is far more important in my opinion…
Make sure you have a back up of equipment, even though its quite rare, equipment can fail…
One big tip, and this is something i cant emphasize enough, make sure you go with active speakers instead of passive, not only are they easier to set up, but if one fails, you still have the other to finish off the gig…
The answer to you’re question is you’re kinda both as us mobile guys have to use mic’s and interact with the crowd…