Good luck! Trust the training you've had in practice. It's my 5th year competing & I'm still a nervous wreck before meets
But once I actually get there & start warming up I relax. Set skill goals on each event, rather than score or placement goals. You can control what you do, not what scores you receive or how you place. Aim to get to the meet about 30 min early. This will relieve unnecessary stress about arriving on time, plus whoever is watching you can get good seats. At some meets, especially ones in smaller venues, these are sparse.
As for what to expect, meets vary, but at most meets, there is a general warmup at the beginning where you stretch & run etc. to get warm. You won't be able to do actual skills on any event except for floor. You can do run through's on vault & find bar settings though. Then, you'll rotate from event to event & warmup then compete at each event.
For hair, I wear a bun for meets. My first year, I used a braided ponytail, but my hair doesn't braid well, so I always ended up with little flyaways. Just make sure whatever you do looks neat and doesn't interfere with any of your skills, and it'll be fine. I've seen many teams use a curled pony tail.
Once again, good luck!
