hello from sydney
My advise is to get in touch with the Botany Bay Yacht Club. It is the home base of the Endeavour yachts up there and you WILL get a crew berth on just about any race and any day with some really good people who will also teach you stuff.
Very friendly and welcoming bunch. You could do lots worse to get your feet wet.
Ask for Colin Cole and tell him I sent you his way.