When I have been there parking in the parking garages is free. Maybe that is what confused them. Is there parking that needs to be validated?
I don't think you can CC but I am not sure. It assumes it is on tribal lands (I think it is) then laws are up to the Indian Nation. Driving through is probably fine but stopping and hanging out in their nation you have to follow their laws but I don't know what they are. Currently I don't have my FL Firearms Law book. Someone borrowed it.