If you are buying from Supercheap or Autobarn, you aren't going to get anything that's in the top of the detailing range.
However, I would suggest as a start from these places, the Autoglym range are quite good for your polish and sealant.
Don't use a sponge use 2 lambs wool wash mitts, one for the body panels and the other for rims and underside. Don't mix them.
Don't use a chamois to dry, buy some waffle weave micro fibre drying towels. If you can't get them from Supercheap you can get them at:
https://www.carcareproducts.com.au/p..._weave_x_large
Get 3 if you can afford it, 2 for the body and 1 for the wheels and other really dirty areas.
Bowdens Own sell a really good car wash (Auto Body Gel).
Buy a product called Vuplex for the inside windows (you can get it at Bunnings or some auto stores). It's a plastic polish/cleaner and its ammonia free so perfect for window tint as it will not harm it like most glass cleaners. It can be used for the outside windows, headlights / Tail lights as well.