who can go to nationals?

Are there any sort of prerequisites for going to nationals? I live in central Iowa and have been rather frustrated by our Masters program (or lack there of). I don't really know if anyone competes (aside from triathletes) and there isn't really any coaching (unless requested). I have never actually been on a swim team. So Masters is my first experience outside of swimming on my own. There are very few swim meets anywhere near us (the ones I've found are all 4-10 hr drive away and not in our zone.. do zones matter for participation?). The closest swim meet that I can find is nationals. As a brand new Masters swimmer, can I go? Obviously, I'm not likely to be winning any races or anything, but it sounds like so much fun to go! And, with all 5 of my kids being on a swim team, it would be really exciting for all of us to check it out. Do I have to have one or two other meets 'under my belt' before I can do this? Thanks for your help. :)