Prices for food are comparable, some things will be more expensive, others cheaper.
Not many affordable single sized apartments around, so get used to sharing with someone.
Never. ever, ever say "Gday mate" with an American accent.
If people ask you are from Canada say yes.
A lot of people will take you to task for every US foriegn policy blunder since Roosevelt....sorry, something you'll just have to live with as the nearest representative of Australia's overlord
or sew that maple leaf to your bag, fellow Commonwealth member!