Hi,
The interview is very relaxed! Who are you, where are you from, what road did you take to become a pilot, what did you like about flight training, what didnt you like etc etc. Very informal. No trick Q's!!!!
Regarding tech Q's what is a what are CAT minima and limits. Maybe even what do you require for the different CAT Levels regarding app lighting etc etc.
The Sim is very easy, A320 sim in a no wind set up. Normal take of to some gen handling then radar vectored app tp normal ILS and Land. Then T/O to alt where they fail an engine. This will happen very slowly so you can trim. Then you do a single engine ILS to land, maybe Go around I dont remember. All very simple. If you are rated they might want you to do a VOR app. I think most is with autothrust so not to hard on the old scan!! Again its all very straight forward and very relaxed. They will brief you about everything! No prep needed!!!!
You can always ask them anything you might not understand. They are very helpfull.
Good luck.!