It is still a rental property as long as it was available for rent during 2018. You will just put "0" for question on "the days rented at FMV" if only available to rent but not rented. Please note that the days that you worked on the home as not considered personal use days. Your capital improvements will increase the basis in your property. (See additional information below if property was not available for rental for all of 2018.)
You will include all rental expenses under the rental section.
Please refer to this IRS link for more information on rental income and expenses:
https://www.irs.gov/publications/p527/ch01.html#en_US_2015_publink1000218984
Please note if the property was not available for rent for all of 2018, you will not enter any expenses under the rental section. You would be able to get itemized deductions for mortgage interest and real estate taxes under Schedule A (as a second home).
