I bought a house abroad (I live abroad), and I don't have a 1098 form. I don't know how to navigate Turbotax's mortgage and property tax sections.

Interestingly enough, the US tax code makes no substantive distinction between United States based real estate and real estate in a foreign country, when it comes to the question of being able to deduct mortgage interest or property taxes.  In point of fact, the rules for being able to deduct either are the same.

Therefore, in order to proceed mechanically in TurboTax, just make your entries in the deductions section as though the Indian home were your home in the United States.

You will enter your qualified foreign mortgage interest as if you had a Form 1098. 

You can take both qualified foreign mortgage interest paid and foreign real estate taxes paid as an itemized deduction on your tax return. Deductible real estate taxes are generally any state, local, or foreign taxes on real property imposed by local government in a uniform manner. 

To enter your mortgage interest in TurboTax Online or Desktop, please follow these steps:

• Once you are in your tax return, type "mortgage interest" into search box on blue dashboard
• Click on Jump to Mortgage Interest (in blue)
• On the "Mortgage deduction summary" screen, click Add a lender
• Enter lender information and on the "Let's get the details from your bank 1098 now" screen, enter your foreign amount paid for mortgage interest in Box 1.  (TurboTax has no separate screen to enter mortgage interest notreported on a Form 1098).

To enter real estate taxes paid:

• Once you are in your tax return, click on the Federal Taxes tab ("Personal" tab in TurboTax Home & Business)
• Click on Federal Taxes tab
• Choose  Deductions and Credits tab
• Click on Show more down arrow next to  Your Home (in blue to the right)
• Click on Start button to right of Property Taxes

This answer does not work because the TurboTax form requires a US address for the lending bank