I'll be playing guitar for 20 years next year and here are a few things I picked up:
1. Don't just do original stuff, throw in a lot of covers (if you weren't planning on doing that anyway). It keeps the crowd engaged.
2. Stage presence is important. A guitarist that makes a few mistakes here and there, but walks/jumps around and looks at the crowd is way more entertaining, than someone who plays perfectly while standing in a corner looking at his fretboard the whole time.
3. Go wireless but keep cables in your backpack. Gives you freedom of movement and you won't be tripping over anything, possibly breaking your guitar (although that would make a superfun youtube video). I can recommend Nux, Positive Grid or Harley Benton - they're at different pricepoints.
4. No string changes right before a gig. Your strings should be broken in, otherwise they're gonna stretch and you'll have to retune constantly. That doesn't apply if you have an evertune, but if you're still in school you probably won't be able to afford a guitar that has one (no offense).
5. Practice your songs a lot. There's a saying that a hobbyist practices until they can play something right, a pro practices until they can't play it wrong.