As long as you satisfy the requirements, you can become a member. These are 18 years old, male, belief in a Supreme Being and no criminal record (no felonies). You don't need to know any masons to get in.
Every state in Australia has their own grand lodge. Just check
for a link to the grand lodge of your state. These websites should either have a contact form or a list of lodges which you can then contact.
You would become part of the largest and oldest fraternity on earth. You would gain brothers. You will learn and more importantly experience masonic symbolism.
Even though we keep things secret, you can find everything online. Only problem is that as a non-mason, you don't know what's true, what means what exactly, etc. But the experience cannot be found online.
I stay because of the brotherhood. I joined for the symbolism and I still learn more every day and feel that it has had a great effect on my life. However, the brotherhood is amazing. Meeting someone from the other side of the world and it feels like you're meeting your life-long brother.
There are dues, but they are not proportional to your income. Mine are 246 euros per year (but they vary from area to area). These are used for building upkeep and whatnot. Every master mason of a lodge can see the finances, so you know exactly where the money is going.