If you're playing at Waterford, make sure you grab a cart. This is quite a long walk with some distance between holes in some cases. The Waverley Golf Club has some quite reasonable membership options. Tirhatuan is also an option if you are not fussed about the condition of the greens.
G'day Kailee. There are a heap of public golf courses in Rowville. The best two would be Waterford Valley Golf Course just of Ferntree Gully Road, Ferntree Gully and the other is Kingston Links just off Wellington Road, Rowville. For a cheap and quick hit you also have Tirhatuan Public.
My family have a membership at Waverley Golf Club (Bergins Road Rowville). It comes highly recommended for golf (affordable memberships) and for events. It is tree filled (unlike Kingston Links being a Links course) so I find it is much nicer to play.