If you’ve never done a USDF show before, or been to one as a spectator, I would highly recommend visiting a show at the venue, sans horse, as a spectator, before you plan to show.
Get the lay of the land. Check out the stabling. Watch how the show is run. Check out what the warmups are like and what the traffic situation is. Get a feel for where you will camp, where you will park, what food is available onsite / in the area, what the drive to/from is like, etc. Watch the competition. Enjoy sitting in the sun and spectating some dressage.
Knowing these things will make your showing experience better and will help to keep pre-show jitters and anxiety at bay.
This is coming from somebody who stepped up from GMO shows to USDF shows by myself, without a trainer, a few years ago. It is a VERY different experience, especially in our region. The hustle and bustle of a multi-ring show full of warmbloods and pros can be a bit overwhelming. Use this gate, not that one! Which warmup am I supposed to be in? Is this ring a bell or a whistle? OMG George Williams is in the same warmup ring, aaaghhh I just accidentally cut him off, what a moron I am!!
When I made the leap, my success and mental health and confidence in the show ring was entirely dependent on having been to the venue before, knowing the layout and situation, having a feel for what I was getting into.
It may feel like a “waste” to drive a few hours, skip competing at the first show of the season, etc. but it is ONE SHOW out of a lifetime of showing. You owe yourself and your horse a good first experience in the big time, and at the $$$ cost of a USDF show, do you really want to feel unsure and unprepared your first time out? Nah. Do your homework so that you can enjoy your “showcation”.