Joined my first club last year, had a great time and learned a lot. I was worried a little how a newbie non-boater would be treated but it was a lot of fun.
The one thing to keep in mind is don't overthink what you are doing. Keep it simple, and try to stick with things you have confidence in.
Also, talk to you boater before the tourney, make sure you know how he wants to do things. Each person is different, it his/her boat so its there rules.