Good luck to you both, make sure your current affairs are up to date for the AIB: they want to see your ability to have a perspective that is as wide and as educated as possible.
Also, know your warships, their roles and where they're based, where they operate at the moment etc.
Finally, know how the training pipeline works (the careers office people can tell you this) so you know what you're likely to be doing in 10 years time.
I joined 21 years ago, via BRNC, and it is the best job in the world. And yes, I am a warfare officer, so I know a little about it!
All the best.