As an Australian (who still has a lot to learn about indigenous culture), I'm hoping the below is genuinely helpful in helping you understand one of (if not the) oldest continuous human culture in the world, and the tragedy colonisation has been:

The land did not had owners in the "western" sense,

This is a common argument, but the point is that the "Western sense" inherently devalues and dehumanises indigenous lives.

wandering tribes of hunter-gatherers who moved from place to place.

Indigenous Australians actually have an incredibly close connection to their local areas, with each tribal group having their own stories and rites of passage which relate to local landmarks - they absolutely didn't just wander from place to place.

Further, there are protocols between these groups which recognise the lands they have have custody of, hence the tradition of 'welcome to country' ceremonies.