I like many people have a very specific image of Aboriginal Australians, which to be honest has mostly been influenced by Crocodile Dundee. The idea revolves around people in the outback of Australia living in arid areas. Australia however is huge with a deverse geography of mountains, coastal areas, forests and more. The different areas must have surely created different cultures but I have no idea what they are, so how did they differ?
There were - and are - many different indigenous nations. The Australian Institute of Aboriginal and Torres Strait Islander Studies has a map showing these nations. According to the Australian government there are around 500 nations. The highest population density was, and still is, around the coasts where people most likely moved seasonally between permanent settlements. Bruce Hood's book Dark Emu gives an excellent overview of Australian cultures before the European invasion.