First time out, start in Novice. Follow the instructors and carefully watch their body position and lines. Look at where your braking points are. Get comfortable with the track the first few sessions. Remember tires don't work as well when they are cold (Under 175 degrees). You probably won't be going too fast, as it is your first time so worrying about cold tires on the first lap isn't as much a problem. As you progress throughout the day, you will be riding faster. I liked hooking up with an instructor early on and following him and letting him take me faster with each session. Keep in mind, you have the best brakes in the world.
Don't brake while turning......it's a no no (Low Side). Don't over accelerate in, or too soon after coming out of a turn (High Side).
Take it easy, relax and breathe while riding. Look ahead of you where you want to go. Especially in turns look ahead, not down at track. Try to relax...you will ride better.
Have a blast, it's what your machine was designed to do.