Hi Jen,
A club doesn't need any formal structure to operate. It can just be just like an informal group of friends and meet at your place.
It's probably better to run this way to start and see what the interest is and if it will fly.
However, you can't set up a bank account in the clubs name unless individual members put their own name and TFN's and provide 100 points of ID on the club bank accounts without an ABN.
When it grows too big, you can start hiring venues for meetings. At that stage, you can just set up a second bank account in your own name or some one else's name to collect subs and pay bills like room rent.
Later, you can consider incorporation.
There are advantages to incorporation. By incorporating, the club becomes a legal entity. I'm not sure how Victorian law works but here in the ACT it gives members legal separation & protection from the club in the event of a law suit.
At some point, you need to step back and let others run it. A club isn't a club unless everyone is contributing energy and enthusiasm.
My suggestion for the club name : Southern World at Night Astronomers. Acronym : SWAN Astronomers
Good luck
Joe