There will be a lot of really good people at that match. A lot of them will be happy to help you be successful.
The advice I give all new shooters is this:
1. Take as much time as it takes to make good shots. Don't even think about trying to get "all the shots off" because you just won't. Not going to happen. Everyone will already know you're not going to get all your shots off, and no one will judge you for it. The fact that you showed up at a match to compete already sets you apart from the thousands of guys on the internet that continually shoot groups at 100 yards but never go to a match. This is an opportunity to work on the basics. Build a good position, with good fundamentals, and break good shots.
2. For your first few matches, you should only be measuring your score based on the number of impacts YOU get off the shots YOU took. If you make FOUR GOOD SHOTS on the stage, and you got 3 impacts, that's 75% hit ratio, and is a good place to start. As before, your focus should just be on making GOOD shots. The speed comes later with lots of practice. Don't worry about speed, worry about making good shots and BEING SAFE on the clock.
3. Start getting your gear together for your turn 1-2 shooters before hand. Be ready to go when the shooter before you is done.
4. Write notes in your match book after cleaning up your stuff at the end of the stage. Note how many shots taken, how many impacts, and anything you want to remember later to work on.
5. Whenever possible, do not try anything new on the clock. If everyone is using tripod rear on a stage, and you've never practiced it, you've only practiced with One Bag, then stick with what you know. Again, you're only competing against yourself the first few matches, understand your skill set and stay within them for now.
Helping pick up brass for other shooters goes a long way.
Have fun, enjoy the time, learn.