Hi There!
Answering both your questions,
First, you can browse through the internet and find all the kira interview questions and answer all of them thrice. Take your time to answer and practice as you have a week to prepare.
As of the business presentation, you can prepare on any topic of your choice, try googling and you might get good suggestions. Make sure you follow the instruction given by the adcom while answering the question or presenting as they pay close attention to it.
Hope this helps!
Regards
S