I'm not an expert at all, but I think an expert needs some basic info to get started.
We would need more info like:
What part of Australia are you in? It is a huge country with probably different climate conditions.
What plants/ trees grow well in the surroundings, this is important!
How big is the land? Is it empty or has it already trees, shrubs and maybe perennial plants in it?
What type of soil do you have? Sandy, loam, clay..
Does the garden gets a lot of sun?
What is the average rainfall?
What kind of garden would you like? A natural one, helping the local wildlife with the accent on native plants, or a formal garden?
