In order of importance, the gear you'll need is: good energy, yourself, someone to play with, a ball, a net, lines, and optionally a roller (or even ratchets for your net setup). The poles to hang your net on are provided by the park district.
If you're looking for a link to buy something, the items below are good value and enjoyed by plenty of folks at Montrose. Fancier versions of all of these items abound and are yours to research.