I'll start by just listing what I know the recurring and one-time expenses that are relatively common for adults:
Unless you live with family and/or have insurance coverage through your parents, your two largest expenses, other than tuition, are likely to be housing and health insurance. In some places, your best bargain will be campus housing while in other locations, it is cheaper to rent non-campus housing. Some housing includes electricity, heat, water, cable and other utilities while in other areas you'll need to budget for those.
books, learning aids, fees associated with Step exams
Travel to interviews for residency
laptop or tablet if you need to acquire or replace
Food,
Clothing,
transportation (vehicle, insurance, maintenance & gas, and/or transit pass and/or ride services)..
medications, co-pays for medical visits, glasses/contacts & supplies.
Hair styling and other salon services (this may be very little or quite a bit more depending on your style and your location).
telephone/cell/internet/cable/streaming services.
Toiletries, cleaning supplies, laundry costs (unless included with your rental).
Entertainment including meals out, drinks, tickets to events
Vacation/wedding travel (even if it just means driving to a campsite or taking Mega bus to couch surf with friends) -- and you are at that age when friends & relatives are going to get married and you'll want to be there for at least some of the celebrations
Gym membership (deep discount or free at some schools) and/or costs associated with hobbies.
You shouldn't need to pay student loans during your med school enrollment. If you are paying off credit cards, you will need to be making those payments.
this doesn't tell you how much you should plan on spending for each of these items because it is going to depend on where you live and your specific needs.
