You would have to set up a miscellaneous expense category called Vehicle expense or something similar. There is no pre-filled expense category for vehicle expenses for a rental property. You would have to assign the mileage to each property based on the business purpose of the trip.
Unless you have a home office for your rental activity, you can only deduct mileage once you reach your rental property and from there to other locations while on business related chores. The mileage back home is not deductible.