Try to advertise with posters and look at your time constraints to determine the max amount of people allowed to enter. I would keep the admission fee to 3$ for members and 5$ for nonmembers.
For me they have it during lunch at our school store. It's important to have the sign ups for monthly tournements at a place people can easiily reach during the school day.
My smash club at my school had a lot of help from another club (Leadership) in planning the events.
