The minimum you need is a volleyball and a net, also a water bottle in case you get tired. Any sporting goods store should have this stuff. Lots of nets come with lines to mark the boundaries of the court, or you can use shoes or other objects to indicate the corners of the court.
Find a friend. You can start learning the basics of volleyball with one other person by playing "pepper;" that is, just practicing the basic skills by hitting the ball back and forth by a bump, a set, and a downball. If you have a foursome, you can split into teams of two and play some games. Ok, good luck and join us!!
