It's hard to tell what the issue is without knowing more about your return. First, if you rented your property for 14 days or less, you are not required to report the rental income and will not deduct any related expenses.
If you rent your main residence more than 14 days during the year and live in it 15 days or more, you won’t qualify for the tax-free treatment. The treatment of the rental activity will depend if you provide services to your guests, in addition to providing rental space.
Most taxpayers are strictly providing the rental, and will report Airbnb rental activity on Schedule E. If this is your situation, begin by going to Wages & Income, then Rental Properties (or search for "Schedule E"). These instructions may be useful: Where do I enter income and expenses from a rental property?
If you provide services to your guests (ie. breakfast, daily maid service) you will report your income from Airbnb as self-employment on Schedule C (or Schedule C-EZ, if you qualify). Begin by going to Wages & Income, 1099-Misc and Other Common Income, Income from 1099-Misc (or search for "1099-MISC").
This article is very informative, and will answer many questions you may have about tax treatment of Airbnb income: Tax Issues When Renting Your Home With Airbnb, HomeAway, or VRBO
Airbnb and don’t own property:
If you are listing your property on Airbnb and do not own it (i.e., you are a renter) you should enter that you own it, and that you are an active participant. In terms of your expenses, you can list your rent but only for the months that your unit was available for rent (pro-rate the rent if you only rent part of your property and live in the rest).
When TurboTax asks about deprecation and mortgage expense. leave those blank. You will not depreciate the property.
