Hi and welcome to BYC - glad that you have joined us. Don't worry about the size of your chicken - its a bantam - the experts will be along shortly and identify what breed it is. Posture-wise it looks kinda girly - but I'm pants at gender so other members will put me straight on that one, I'm sure!
If you are intending keeping it, I'd suggest you look into getting a couple of friends - chickens are social animals and thrive in a flock environment.
Not sure if you are intending building a coop etc but the Learning Centre is a good place to start, as is searching threads on topics of interest. There's also an Aussie thread - "Australia - 6 states and that funny little island" which you may find useful in terms of finding other BYC members close to you.
All the best