So, after a bit of looking around I found a vet clinic not too far from my house, which has emergency services (fingers crossed that I don't ever need it) and a staff with a few different vets. I went in alone to check out the place before making the appointment, and it seemed pretty nice, the waiting area was clean and not chaotic. And what I saw from the staff, they seemed great and really helpful. So I made an appointment for Monday, I need to get Rizzo's anti heartworm meds refilled, and Fatso needs some blood work done, I'm pretty worried about the big guy. I fear he isn't loosing weight at the rate he should be, and he just keeps getting lazier and lazier.

poor guy, I hope I'm just being a nervous ninny, but I won't know until a professional takes a look at him and does some tests--I fear it may be diabetes, but that isn't the worst case scenario.
Anyway, what kinds of questions should I ask of my possible future vet? I didn't really have a wide variety of choice in Italy (language barrier) so this is the first time that I actually can shop around for the right vet. I tend to base most of my decisions on gut instinct, but I'm afraid of showing up Monday and acting like a ignorant pet owner who can't untie my tongue.
Any words of advice? I hope he's a nice guy who will prove to be helpful in getting my kitty cat healthy again.