Anyone can go! I've been to the one in Arlington twice, it's a nice show and I'm deeply disappointed that I have to be out of town that weekend...

The show's website located here will have all the information you should need. There used to be cupons you could find that made admission only 12 dollars or something like that, but idk where that is now. Saturday would be the more ideal day to go if you had to pick only one, as all the vendors run out of tanks and terrariums by halfway through the show on Sunday (Holy crap, you can't beat the terrarium prices anywhere, buy one here if you need one).

I highly recommend going, they've got awesome vendors, awesome animals, and it's overall a great time.