Hi Foxy
In addition to Sasha's advice (which Ive also found true of both the interviews Ive had) I would advise that you write down a list of the questions you want to ask yourself and take it along,its easier to write them down and then you cant forget if your a bit flustered which can happen
I always ensure to ask
What commission to the agency charge per booking?
What percentage do drivers charge per booking (if you need to use them of course)
How do the agency run checks on potential clients to ensure your safety?
What is the procedure for when you receive a booking,i.e,do the agency ring or text you? do they require you to ring in when a booking with client starts and again when finished to let them know you are safe? (I would say that any agency that values your security should insist you do that)
Photos,if agency wants you to have them done with their own photographer will you have to pay towards these? will you have the rights to the photos?
Ive also found agencies will ask which age ranges of clients you are willing to see.
Don't be scared to ask as many questions as you want,even if they seem silly,a good agency should be willing to answer them all and want you to be happy working for them.
As for dress,i wear a nice,sexy but subtle dress and like Sasha says High heels cos they give you confidence even when your quaking in your boots
Good luck and let us know how you get on.