I think there are a few factors you should look at:
1. Program- the undergrad programs are relatively the same for different universities, but still do your research.
2. Opportunities- some schools provide students with more opportunities for research and EC involvement, which is also dependent on the school's location
3. Location- See which location works best for you. Do you want to live at home and commute or live on/off campus?
4. Expenses- Calculate the potential expenses such as moving, renting, commuting, tuition, etc.
5. Campus- Campus tours can really help you finalize the decision if you can see yourself fitting in or not.
During your studies, you might find interest in something other than medicine, so make sure you keep that option open.
GPA is key, and so are ECs. Good luck with making the decision!