Mid-O is a fantastic track. The extreme elevation changes in the back section will slow you down at first, because you can't see which way the track turns next. For that reason, I think it's very important that you study videos and the track map as much as possible so that you have the track memorized before you get there.
Although - as Ian said - SBTT is a great group of people, and they will help you out, and help straighten out that learning curve.
(also, you might want to make sure you replace your antifreeze with water, or water wetter, or "blue ice/engine ice"... I'm not sure if that's a rule for the beginner group - so you might want to check that out)
(click here for rules)