>>126648 (OP)
I have lived out of a car before and would do it again before sharehousing again.
I have never been to Brissy but you have to know where the free showers are. Beaches are your best bet. Recharge your phone etc at a library like a smelly backpacker.
Woolworths has cooked chickens and baked potato or potato bake most afternoons. That stuff is more wholesome than takeaway.
Cooking on the streets is hard because you get noticed.
Are you sleeping in a car or actually on the streets?
I don't know your situation but have you tried finding a cash job (who cares how jewed and low paid) and looking for short term accomodation through gumtree or similar? You sometimes get good deals.
A good tip is to air your clothes every chance you get so you don't end up with that musty hobo smell.