Aussies are rare and expensive ($1000 ). Unless you specifically paid for an aussie from a honest breeder, you have a NG.

As far as cages, I have gone over this in detail in previous posts. For starters, I like the Exo-terra 24x24x18 glass terrarium. It is easier to maintain proper temp/humidity in this size cage, compared to the big phone booth size cages that some people build.

This Exo-terra would be cramped for an adult male, but OK for an adult female or sub-adult male. See my previous posts for photos and setup instructions.