Congrats on deciding to do a meet. My first will be at the end of June. As far as a "respectable total," don't worry about it. You don't want to have some number in your head that you must have before you are "allowed" to compete. I'm assuming your young and so if you compete against others your age, and thus likely to have similar experience to you, you will have a chance to be competitive. The experience will probably be worth it not because of the total, but because of what you will learn at the competition.
Once more, I haven't competed yet, but I look forward to it as an opportunity to learn more about lifting and to meet some new people (especially those that can help me). As far as my total, I'm keeping my goal very modest.