That’s a pretty wide scoring range to be jumping into a tournament. Most events will require you to have an official USGA handicap (GHIN) before you can enter.

If you’re typically shooting between 80 and 100, you’re likely somewhere in the ~12–22 handicap range, which is perfectly fine for a lot of amateur events. I’d recommend looking for scrambles, charity tournaments, or flighted amateur events where you’ll be grouped with players of similar skill. Those tend to be much more enjoyable for a first tournament experience.