Burger King is called Hungry Jacks.
Don't get involved in football clubs. You will be crushed by a bogan wielding a VB, and that's no good.
There is a difference between gas and petrol, but no one knows what it actually is. So get petrol.
Here is a brief, extremely incomplete, list of things they say and their American equivalent:
car park = parking lot
footpath = sidewalk
shopping trolley = shopping cart
serviette = napkin
tomato sauce = ketchup
lemonade = sprite / 7up / etc
chips = french fries
crisps = chips
New Zealand = funny accent
American = "I bet you can't even tell me who our prime minister is!"
seppo = derogatory term for an American (it comes from rhyming slang, eventually, but that's a whole can of worms I can't begin to describe accurately)
There's plenty more, of course, but I'm tired of that.
Be wary of roundabouts, if you plan to drive. They take some getting used to. And you'll be on the left side of the road and right side of the car, of course.
Toilets do not have handles, they have buttons. One usually is a light flush (for piss) and another is for a 'full' flush. And they will all be low flow.
There's a long drought going on so there are lots of restrictions on what and when you can use water. It's worse during the summer, of course, and it depends where you're going.
That's all I can be bothered to think of. Have fun