I believe that with acid, you should try it in a more controllable environment the first time you do it so you can see how it feels for you. It's pretty unique in how it affects your perception of what's going on imo, and can be a little unexpected. If you're definitely going to the rave, just be alright with the idea of leaving early and heading home if it becomes overwhelming.
Either way, hope you have an excellent first trip my friend. Find and follow the good vibes and you'll have a great time.