You're definitely on the right track to realize that you need to familiarize your dog with the show environment. Many times it takes people some time to realize this.
I like to take my dog to training classes because it gets the dog accustomed to working in an environment where there are other dogs and I think that's particularly important for the stays. If you train at an obedience training club they may actually have matches and trials there from time to time and if you entered them your dog would be working in a familiar environment. Your trainer could probably tell you other places where you could enter matches and whether you might be able to visit them with your dog for acclimation to the show environment without actually entering. Large outdoor events are probably the easiest to visit. Smaller indoor events are, for good reason, more likely to strictly limit access.
Stewarding at matches or trials is a great way for you to observe more experienced teams and learn.
The AKC lists trials https://www.apps.akc.org/apps/event_calendar/
You can search it for shows in your area and visit the shows. I like to do this before even taking a dog so I know what I'm getting into. It's amazing how much variation there is . . . even indoor trials can vary from small trials which may be limited to beginner and novice classes to huge multibuilding shows that include conformation, obedience and agility trials being conducted simultaneously.
If you're in the Northeast there's Match Show Bulletin - Home
which describes itself as "the one source for information on dog matches, both conformation and obedience, as well as rally events, agility events, herding events, weight pulls, tracking events, health clinics, canine good citizen and therapy dog testing, seminars, workshops and training classes." My trainer has mentioned this but I've never used it.
Sunfire's Amazing Grace, CGC, CCA, Pet Partner therapy dog, 9/12/2013 Zoe
, Rockwall Nantucket Breeze, BN, CGC, Delta therapy dog, 5/4/2008 - 10/28/2013 Zeke
, our introduction to the world of Golden Retrievers, 6/12/1997 - 12/18/2007