If i to travel to australy i can to find i friend to rent me a cheap flat there ?

Answer 1

Try www.melbourne.craigslist.org or sydney.craigslist.org they are free websites you can advertise for flatmates. Otherwise put signs up at the local laundromats and language schools where you want to live and it's likely someone will call you.
Good luck with your trip - save as much money as you can before you get here.