Starting a club with three members still counts as founding something.

Three people is a real club. The number only looks small next to something that had years to grow, and most large things you admire started with a few people in a room. Founding is the unglamorous setup: the booking, the asking, the showing up when only two came.

If you have been waiting for enough interest before you start, stop waiting. Ask one teacher for a room and two friends for a Thursday. Keep it going for a term before you judge whether it worked.