You can get demos, traffic counts, etc from Costar but that is a very expensive subscription. If the property is for sale by a broker, ask the broker to provide you with this info. A good question to ask would be to see the actual annual expenses to verify the NOI and cap rate. Also, what kind of leases are the tenants on. If the tenants are on triple net (NNN), are they all paying their share of the common area maintenance (CAM) expenses and have they been updated regularly?
Property management fees where I live in LA, CA is generally about 5% of the base rent, meaning the rent only, not the CAM if the tenants are on NNN leases. If they are on NNN, then management becomes a bit easier in that you do not have to go around fixing toilets and every little thing that goes wrong in each tenant's unit. You'd have to read each lease to make sure but that's generally the case. For NNN leases, the landlord has to maintain the common areas, meaning the parking lot (cleaning of it, lighting, repairs, snow removal), sidewalks, trash cans in these areas, landscaping maintenance, the roof of the building, rubbish hauling, exterior building lights. It's not hard, just a learning curve after which it's just regular maintenance.