My son didn't have a very good prelim competition - had two falls in prelims and just think nerves got to him - his AA score was a lot lower than regionals, and he had his season lowest score on one or two events. But he did qualify for event finals in two events. In both events he got his highest scores of the season, and in one event he was in 5th place (medal to 6th for events) with two kids left to go. Well, they both scored higher so he ultimately came in 7th just missing a medal, which is still amazing in one of his weaker events typically. He was happy though, he was actually glad about the two events he qualified for event finals because he wasn't nervous about them so it took the pressure off.
The most important thing was he was nervous as it was his first national competition, and now that he has been through one, he doesn't seem so nervous anymore. I think he can now look at it as just another meet.