I'm sure. Very very few of these types of things are invite only. Bring ammo, somebody might let you use their gun. I've done it.
Most competitions invite spectators to come watch, as long as they bring ear/eye protection. ENGC matches are always open to everyone. (And if you come watch, you are going to want to shoot it the next time. Or if you are lucky, someone will let you borrow some gear and shoot it THAT time!)
As a quick comment, the ENGC Zombie match includes a .22 rimfire division---and you don't need a holster, either. About all you need is a pouch to hold extra mags, and plenty of ammo. So there aren't any excuses for not shooting the match!
The Alliance match looks like a lot of fun---but unfortunately, it is a bit far for me to go. Hope you get lots of people from your side of the state!