Find one of the NFOA guys like bkoenig or JTH and follow them around. Ask questions. Gun guys love to talk about their hobbies.
The hard part is making us shut up!
You can certainly come out and watch a match---talk to people, see how they are run, what is required, etc...
....but if you do, you are going to want to shoot it. So like bkoenig said, if you have:
1) semi-auto rifle and the ability to carry at least 45 rounds on your person (ex: AR-15 and 2 30-round mags),
2) semi-auto handgun 9mm or larger, plus the ability to carry around at least 35 rounds of ammo (ex: Glock 17 and 2-3 magazines), plus a decent holster that covers the trigger guard and keeps the firearm secure, and
3) shotgun (20 or 12 gauge) and the ability to carry pretty much a whole box of extra shells (which, I'll note, people have done successfully by dumping them all in their pockets)
....then you are good. It is unlikely that for your first match, you'll be directly in the running for 1st place.
As such, just bring equipment good enough to try it out, and concentrate on safely navigating the courses of fire. AFTER you've tried it and have a better idea of what it is like, you can think about changing your equipment around.
Here's what a match looks like, from one perspective. (Ignore my poor shotgun loading skills!)
Here's another one:
And also like he said---if you decide to shoot, just let the registration person know this is your first time, make sure to show up for the safety briefing at 8:40, and when you get to your squad, tell your RO that you are new to this. They'll help out.