Your wing, harness (with reserve), helmet and gloves are all you really need to go flying, however there is an almost endless list of other pieces of equipment and associated software that can be purchased ... and that can maybe distract you from getting in the air. remember to check Aus PG Buy, Swap & Sell if you are looking for gear.
Vario - to give you those sweet beeps as you get lift. There are many available but new pilots could use a low cost unit like the excellent BlueFly.
Radio - you really should have one ... and it should be certified for use in Australia. UHF to start with and then later when you really get into XC, an airband VHF. See Fly Manilla.
Flight Instrument - not really needed by new pilots ... who don't need that sort of distraction. But excellent software is available for your phone. Android - XCSoar / TopHat and iPhone - Flyskyhy but there are many simpler apps available.
The Club has purchased a porosity meter and club members can arrange to have their wing tested by contacting the President and arranging a time for the test (usually before or after a club meeting). This service is free for members and $35 for non-members.