I think a hostel will burn a hole in your pocket and you won’t have a nice feeling of going to your own place if you do it that way.
Why don’t you try looking on www.gumtree.com.au for any vacancies? You’ll be able to enter a shared flat or apartment or something. It depends on your budget also. If you go to Gumtree you can enter a Sydney search and specify your maximum rent per week in whatever area you prefer. I wouldn’t commit to anything that you can’t see in person however, so perhaps you should stay in a hostel for a little while until you can find a place you like? That’s what I did while I’ve been living in London and I found heaps of possible places (even though many of them were quite shabby…but I was looking at quite a modest budget.)
Anyway good luck. I suggest you look at some places on gumtree prior to your trip to Australia just to get used to the website layout and see what kind of things there are available. That way it should be easier when it comes to the actual search, and you’ll know what you want a little bit more.

Hello
Thanks so much sophsicle for your advice. It is much appreciated.
Happy Travels