May I ask how in the US you normaly become a member of a dojo if not by signing a contract?
I've been a member of 4 dojos. None required a contract.
Each required a modest annual fee + that dues be paid monthly.
Two of the four were set up for automatic credit card billing, but this could be stopped easily in case of withdrawing due to either a temporary stoppage (leave of absence) or permanent one (stopping training).