You need to apply for a tourist visa through the Thai embassy in Canberra that will give you 60 days, then just before the 60 days are up you go to immigration with passport and passport photo copy of passport and copy of your 60 day visa plus 1900 baht.
Post off your visa application about month before you depart sent it registered post you send your passport a photo a bank statement and a registered post envelope with your address on so they can post it back and a money order for $60