Here is a link to various wildlife rescue groups around Australia.
Now this is just my opinion.
If you are concerned about helping injured wildlife it is almost the major danger period as young will be out and about soon.
The above link may help you find a local group. Put the telephone number in your phone as it may be too late with an animal in distress needing help. There are many dedicated volunteers who can care for or euthanise an injured animal. They will also check for young in the pouch of a marsupial. Your local vet may also have a list of carers.
If you find a baby bird it is best to leave it alone and watch from a distance as it is most likely still in its territory and the adults will be around and keeping their distance because of you. Put it in a safe place near where it was found and see if the parents return.
I saw a Facebook post from someone who found a baby magpie whilst cycling. He picked it up off the road and cycled some distance and released it. There was a large and heartfelt response to the post but in reality he probably killed it.
The parents are the best ones to care for their young.