So here's a list of things you'll need to get, I'll also throw in some key words for you to search for (because I can't pick everything out for you plus I don't know what sales are going on in your region):
CPU:
Intel or AMD brands are your only options.
For Intel: i7 7700k, i7 8700k, i9 9700k
For AMD: Ryzen 7 2700X, Ryzen 5 3600, Ryzen 7 3700x
These would fit your budget and are recent enough to perform well. The order goes from oldest to newest.
CPU COOLER: (this can be determined once a cpu has been chosen)
MotherBoard: (also requires a cpu to be chosen first)
GPU: I'd say go with a 2070 Super (~750AUD)
RAM: (Anything DDR4 between 2666Mhz and 3600MHz)
Storage: (a small 250GB NVMe for OS) and a 1 - 2TB HDD for storage and games
Power Supply Unit: (Anything 600W would be ideal for a 2070 Super, just don't cheap out on your Power supply. That's a big no no in the pc building world)
Case: (will vary depending on Motherboard and Power supply choice)
So just fill out or ask questions about each option as you progress and you should have yourself a custom build. You can use a website like pc part-picker to choose each part.
https://pcpartpicker.com/ Just look for the items with the keywords I used in each section.