I’ll be arriving Perth on Feb2,2018.
Looking to get AUD in exchange of USD since i will be flying in from the Philippines to take up masters.
The most cost-effective way to get AUD is from an ATM using your bank debit or ATM card. You may incur some bank fees, but the exchange rate will be much more favorable than what you'd find at money exchange booth. Also, it's MUCH safer to get money from an ATM as needed as opposed to carrying wads of either USD or AUD.
A bank or a city money changer (bureau de change) is likely to give you the best rate. It's a bad idea to use an airport bureau de change (especially Travelex).
If you are coming here for some time, presumably you will be opening a local bank account. You are likely to get a reasonable exchange rate and avoid fees if you change and deposit the $US into your account at the time that you open it. Bank staff have the discretion to waive fees and are most likely to do that if you are doing something nice like opening an account.