Questions to ask when shopping for a Bank Mortgage

Hello.  We have not made a major purchase of any kind outside of a vehicle.  We want to purchase a duplex, triplex, or quadplex, live in one unit and rent the other units as a way to get started.  We are leaning toward shopping for a mortgage from a bank.  What kinds of questions should we ask to ensure we are getting the best deal for that type of financing?  Thank you for your help