I've raced mountain bike races for years and even 10 years into it, don't necessarily ride all the parts of the race, I will get off and walk if I need (sometimes the uphills are just too hard too); so when you dismount, get off the side of the trail so people who want to ride can get by, when you run down a drop off, make sure you have room to go before someone riding might run you over; when you get to the bottom, get off to the side, make sure no one is riding behind you that will run into you and get back on the course.

GO FOR IT! GO race, and start in the beginner's category. If you are better than that, you will find out quick enough.

spoke