Sorry you have had no replies. It's a long time since I had an interview so I have held back hoping someone with more experience would chime in.
It's worth reading the threads on here to learn a bit about how the industry operates and GNE in particular.
Drop in stuff like customer focused, punctuality, emphasize that you are rarely late, good people skills. They are likely to give you examples of problems you might encounter, difficult customers (always use customers, not passengers and definitely not punters!) for example, or people complaining about you being late.
Have they been clear on your hourly rate and other things like shift length and conditions? If you really need the job I wouldn't push too hard at the interview but you need to know stuff like this before you are committed. They appear deliberately vague on things like this now.
There is a joke in the industry that 3 people turn up late for a job interview and the first thing the manager says is "when can you start?"
In fact I have stopped telling people I have a PCV licence as I was sick of being offered work.
Anyway, good luck.