Yup,
questions etc can't be too technical coz you're not in the job yet.
Probably ask what you understand by 'Health & Safety' and if you've come across an instance of it in you're current job,Same with 'equality'.How you feel about carrying out Community fire Safety visits, working within a team, working under pressure etc.
They're really just seeing what you can offer and if you've got common sense !
May ask things like ' How do you think you would react if you had to cut a badly burned body out of a car?' just be honest, if you think you'd vomit then get on with the job , just say so. They're not trying to trick you.
If it's anything like my interview it was pretty informal, me, Subby (WM!!) and Station Officer from Wholetime unit.
Best of luck, you won't regret going for it.