Have you read Deadly Unna?
It's a really, really good example of a text that uses lots of Australian English and non-standard usage too. We were given it as a bit of an introduction to Eng Lang. There's a little bit of dialogue if I can recall correctly.
Honestly just troll through your school's library a bit. Plenty of fiction novels have heaps of Australian colloquialisms and all that jazz. Check the authors Nick Earls and Rebecca Sparrow, I remember reading their combined book "Joel and Cat Set the Story Straight" in like year 8 or 9 and picking up those sorts of things but don't quote me. All of those girly teenage-y novels about going through adolescence and looking for boys and not being popular and all that superficial stuff and shiz that you really only see the year 7s at your school flicking through is PERFECT and are AWESOME resources for this task.
How is this helpful, you ask? Think about it. Teens in particular have their own way of communicating: "Teenspeak". They also invent new words (neologisms) to be able to identify new things in the evolving technology age. Think about acronyms too. Why do they do this? To exclude and include. To ensure adults don't know what they're talking about. To use diminutives of words about places, people, whatever so that they sound cooler being shorter.
So go forth and absorb all!