Elixir,
Don't panic too much about it. You will get some familiarisation time with the sim and the company bloke will brief you about all of the instrumentation you require and tell you what not to bother about.
They are looking for your basic flying skills and, probably more importantly, your CRM and team skills.
Best advice I can give is to relax as much as you can and enjoy it. It's much, much, much nicer than the old BAC1-11 sim ;-)
Good luck
