Hello!
Congratulations on the AC invite!!
The main resource that I used when preparing for a case study interview was
this guide by Jacob Miller - I would definitely take a look! There is also a guide to Private Equity that is useful for understanding how a PE transaction is structured -you can find that
here.
I have also quoted some more general posts I have made in relation to approaching case study exercises, so hopefully they are helpful too.
Best of luck!!