Hi, CTC doesn't actually stand for anything. I think it used to stand for Crew Training Center but as far as I am aware, it doesn't actually stand for anything. When I did my interview I spent ages trying to find out the meaning of it in case they asked. You won't be asked though.
For the sim, you can't do any prep at all really, you will be shown everything you need to know and then the sim session will be based on how much experience you have. When I did mine I had 20 hours experience and so the guy who did my sim took control of the thrust levers and I literally just had the control column and was asked some mathematical questions.
Good luck to you all