http://www.worcsracing.com/images/stories/flyers/rnd2_flyer_back_11.pdf
above is a link posted for this weekends upcoming WORCS race in Primm, NV. the flyer for the Idaho race won't be available until about a month or two before the race, but the race flow is roughly the same for all races except the Primm race is kind of an oddball because the Bikes and Quads run the same weekend (same place but different tracks) and there is no friday practice for this event.
you'll notice the unclassified race saturday morning around 9am. that's the busiest race as it's the only time the participants can view/ride the entire course, and predominantly used as a practice session. it's about half price the regular events.
around noon on saturday are the age oriented C classes which you should be in. you will be more comfortable in this field as there will be alot of first time racers in the series, and a wider variety of machines and modifications.
the open and production c classes run first race sunday morning. race this class if you can't make the saturday races. be aware that they will be performing sound checks prior to race start, and there are no refunds for not passing.