Do you already do any camping, backcountry camping or at least car camping? How about bicycle maintenance, I would think that any class in bicycle maintenance would be handy and if you start camping, you'll gain experience in that regards. In effect, bicycle touring is a lot like backpacking, except instead of hiking your gear around in the woods, you're cycling it. I know all my ultralight backpacking gear (camp, sleeping bags, stove) get used for my bike tours so if you are already a camper, the same experiences for camping you can use for bike touring. I never took a class in bike touring, but I alrady had a large background in both cycling (on and off road) and backpacking, bike touring was just a natural extension of cycling and camping.
One thing that is different is bicycle maintenance, the ability to improvise when things go wrong many miles from home and mental preperation which is best learned by experience. Then there is stamina and physical limitations, know your child's limitations, etc.