Get your paperwork in as soon as you're able. I wasn't able to book my assessment day until I had all of mine in.
Mvdia, I was asked what aircraft I might fly in the RAAF and what aircraft the Army flies as well as what I would fly, given the choice. Very basic stuff that takes 5 minutes to learn.
The Army captain that interviewed me said I'd make a good officer, she then continued in saying that's a good thing coming from an Army officer to a RAAF applicant.