Absolutely dress nice. Slacks an dress shirt at minimum. And show up 15-30min early.
As far as interview questions, it'll be pretty standard I'm sure. Stuff like "Describe how you have/would handle a difficult patient." "How would you deal with a partner that has different ideals/morals than you" "Describe a stressful situation you've had and how you've handled it" Stuff like that. Never give just a yes/no answer. Validate or elaborate on everything you say.
Good luck!