Your boyfriend is discouraging you? WTF? Why would he do that?

Almost all races have a beginner category -- that's what it's there for.

Maybe you can really scare the crap out of him -- I noticed that mountain cross event at the Keystone Climax is free to beginner and sport women, probably because they don't get enough of those. Mountain cross is kind of like motocross on a mountain bike with four people on the track at once. Looks dangerous.