I would triple- (or quadruple-) emphasize practice and rehearse.
In addition to practicing and preparing in the studio, I’d also recommend doing at least a few dress rehearsals. Book a few hours in a separate rehearsal space and run through a full mock gig night. Repeat the process once or twice per week leading up to the show, with studio practice in between, and maybe two days in a row before the gig, if time and budget permit.
The goal of using a rehearsal space for the dress rehearsal is to also practice the “getting to the gig” part of the experience, and to build your experiential memory of how to handle curve balls, which should help reduce stress on the night of the actual gig. If your area has the means, try doing each dress rehearsal in a different space so you don’t get too comfortable.
Treat it like a role-play of the actual gig: tear down your gear in the studio, pack it up, head to the rehearsal space, set up the gear, do a short sound check in the rehearsal room, take a 5-10 minute break, run through your set exactly once, then pack it all up and head back to the studio. If you have the time and energy, set it back up right away so you can reflect on the set, and resume normal practicing.
From this, you should hope to learn:
- how long does it take to pack up your gear in the studio?
- how long does it take to set up your gear in a new place? (load in)
- how long does it take you to tear down your gear in the new place? (load out)
- what cables / adapters / moral support tchotchkes did you leave at home?
- how difficult is it to transport your gear from studio to rehearsal space?
A few other notes, that come to mind from electronic music courses, and various experiences:
If you can contact the venue beforehand to get a list of their gear, do it. It will help alleviate the power/DI/cables/monitoring stress a little bit.
As others have said, bring only what you need. Use the dress rehearsals as an opportunity to refine that.
This includes costume / wardrobe. Dress up for the dress rehearsal (or pack your clothes and change at the rehearsal space, if that’s what you’d do the night of the show)