Firstly good on you for considering this career path, I wish you well. I had no idea where I was going in life and if I hadn't joined God knows where I would be right now. It is great to be part of a cause bigger than yourself and the mates you serve with are lifelong.
Pilots are trained as officers and are generally smart, it's a sought after role. You will need a basic understanding of year 12 advanced mathematics and physics before you apply. Hit the books if you're not up to scratch.
In regards to psych testing just tell them what they want to hear. Physical and medicals should be easy enough but I would go about your own training beforehand. Swimming and dog-paddling are critical for pilots as ditching in the ocean is trained for, wear clothing in pool to increase resistance. Running (beep test and distance) and bodyweight exercises (pushup, situp, heave) will also help you smash the physical.
Here is some more info, try and learn as much you can about the position and it will show recruitment you are serious and keen. It's all about initiative.
https://www.defencejobs.gov.au/jobs?tab=view-all-jobs&page=1&perPage=21&query=helicopter pilot&jobStates=full-time&msclkid=6dcd6388b7951886f9fc3cab8c45bd80&utm_source=bing&utm_medium=cpc&utm_campaign=Brand | Defence Force || Aus | Exact | Search&utm_term=adf&utm_content=Brand - ADF&gclid=CIaexv319eoCFQRnjgodQ5YKNw&gclsrc=ds