SGU student here. I had my interview a little over a year ago. Some things they asked me and most likely will ask you the same (they just read questions off their laptop and type in answers):
Why SGU and not US schools?
Why not Ross/AUC if you applied/got accepted?
Why med school/medicine?
What type of medicine are you interested in? specialty?
Explain how you can handle the stress of med school/what do you do for fun to destress?
Explain how you can handle being away from home and in another country/underdeveloped area without all the luxeries
Give your strengths and weaknesses
Explain any leadership positions and research
How will you pay for SGU? (they want to make sure you know how much it costs and how you are paying for it)
Explain your shadowing/medical experience
What does professionalism mean to you
Other than that, I remember there were a few oddball questions but forgot what they were exactly.. I think one was what was my view on healthcare and insurance or something.. another one was I think on what would I do if I saw a student cheating.
Just smile, be polite, respectful, thankful, personable, and mature. They want to see professionalism, maturity, interest in medicine, and readiness to start. Also, after the interview send a thank you email to the person that interviewed you.
If you have an interview, your grades and MCAT are good enough (either regular MD acceptance, MSAP, or charter foundation program). They want to see how you communicate and present yourself. There's a lot of immature unprofessional kids at SGU, yes I said kids because they don't behave like adults... they slip through the interview process somehow, so they want to see someone mature and professional- super important.