For the Challenge of the Americas, there is menu item called ‘Rules’ that has all the different regulations you must know: http://www.rotaxchallenge.com/
Memberships depend on where you race. Most of the time at the local level, you don’t have to be a member of anything – however – it is encouraged to joined the local club to be involved more. Regional level may require a series/sanctioning body membership, others don’t. Most of the national events you need to be a member with the organization (IKF, WKA, SKUSA, etc.)
I read the relevant SKUSA rules. I see why they article said I should read them. There were a lot of things I didn’t know, that I see are pretty important. Thanks again everyone.