I'm about to give way too much info,

. If you want to make it the best possible gig you can have, adhere to it. If you want to have as much fun as you possibly can, maybe not, lol. Its just some things you might want to consider.
Has anyone yet mentioned bringing your amp?
If you don't, you run the very real risk of not being able to hear yourself, and the near certain risk that your bass will sound nothing like you're hoping it will.
Outside of that, if you're worrying about screwing up and silly things of that nature...
1. Know that you WILL screw up, as will others, and its fine. There's no point in getting upset with yourself or you bandmates. Most won't notice the flubs.
2. If you want to make screw up minimal, its a good idea for your entire band to go through all 5 songs, on their own, playing to a click only - to be sure they know the songs inside out. The reasons for that are in 3 and 4...
3. Don't expect your band to sound anything like you're used to. It might if you're lucky, but chances are its going to sound like you're playing in an entirely different band with different instruments. You will NOT hear things the way you're used to hearing them, and there's a possibility that you might not hear the guitar or vocals at all.
4. If number 3 happens, you might be very surprised at how much your band depended on other cues (vocal, guitar or whatever). Knowing the songs inside out, upside down and backwards can be super helpful if you can't hear things well or another member flubs something you've unconsciously been using as a cue.
5. Look up. And do your best to smile, even if you're scared crapless. People like to watch people having fun. Looking at the audience is a good thing. If it makes you nervous, looking above their heads serves the same purpose.
Plan to show up an hour before you're supposed to. That goes for the entire band. Especially the drummer.
6. Be kind to everyone, even if they're jerks to you. Vent later among yourselves.
7. Do your best to interact with, look at, or at least acknowledge the other members of your band while playing.
8. If you or anyone in your band believes in God or any sort of higher universal power, or even a higher, unconscious inner self - turn the gig over to that power, and trust. As corny as this sounds, when I'm nervous I like to think of the audience and tell myself I'm there to bless - not impress.
9. Dress thoughtfully. This is a personal band choice... but I think it matters lots. When a band looks like a band that band becomes more memorable. If one person is dressed like an 80s hair band and another is wearing shorts, sandals and a T-shirt, that's obviously not going to fly too well. My go to is almost always all black as it seems to work well with anything and everyone.
10. And I'm sure there's super important stuff I left out. I'm equally sure someone else has or WILL cover it.
Enjoy!!!!!
And make sure you come back here with a gig report and pictures.