Don't be afraid to go to your first match. Everyone has to start somewhere. Provided you follow the rules, other shooters are always happy and willing to answer questions and help you along. Offer to help out. The vast majority of competitions are conducted by just a handful of volunteers.
Extra help is always welcome.
Granted, you've paid your entry fee and are entitled to devote your attention to your shooting, but you can still offer to help on the range after the match, put away equipment or any number of other tasks. Without the people who give up their shooting time in order to provide it for others, there wouldn't be a competition. So do your part as a competitor. Be sure clothing worn to a competition reflects your concern for comfort and safety as well as recognition on your part that competitive shooting should be represented in as positive a manner as possible. Especially when TV or newspaper coverage will take place, attire should be in good taste in order to enhance the image of this sport being conveyed to the general public.