Glad you signed up.
The hardest part for me for my first PRS event was getting on the first target of the stage once I got in to position. Mostly because I'd forget to set parallax first. LOL.
Usually, during the zero session, someone will have a chronograph. So you can plug in that info in to a ballistic solver to get dope. You will need to know your scope height over bore for your rifle. So measure that now. It would be best if you can zero your rifle at 100 and get the ammo you plan to use chrono'd ,now at your home range. It will change slightly between your home range and the match range though, but close enough to at least get started.
The other thing I learned quickly, is that getting behind a rifle on a bench is way easier and faster than holding everything until a beep goes off, and then trying to build a stable position with you rifle on a rope. LOL.
Practice that part now. Get a 22lr rifle and go to your range and place targets in varying places and practice getting in to position and acquiring that target.
Your best plan should be to find a PRS 22 or NRL 22 event in your area and sign up.
You will most likely time out on most stages. Don't worry about it. Slow impacts are way way way better than fast misses. So hit what you can, and don't worry about clearing a stage.