I have been sailing with monohulls In the Wed Nights on Clear Lake for 9 years now and periodically at Houston Yacht Club for about 10-11 years. In general it has been fun and worth the effort to get to know the "main stream" sailors.
In general the problems have been boats that don't see you, the Mark roundings and when the winds demand you go thriough the middle of the course or through spinnaker boat "line" downwind. For boats that don't see you, you just have to watch. For the marks, just stay clear and stay out of wind shadows. It's just not worth the effort to fight it out. Also in heavy air, give spinnaker boats plenty of room at the leeward mark. You do not want to be anywhere near them if they can't get the spinnaker down. Downwind through the middle of the course, be very careful. Wild Thinging a Tornado or an A-Class through the spinnaker boat line is a cool and scary experience.
If you have the chance, start with the Lasers. Sharing a start line with a bunch of Olympic Wannabes gives you some good experience. Also their tacking upwind in light air can teach you some things.
You will learn some new techniques.
"scrape" - use the line of monohulls to scrape your opponents off.
Shadow - Sucker your opponent into a big boat's wind shadow
Slam Dunk - use your wind shadow to induce a "death roll" in the Laser that headed you up at the start.
Carl