To use the Free Edition of TurboTax, a return needs to be filed using the standard deduction. Mortgage interest and property taxes are itemized deductions and to include them in TurboTax, you would need to upgrade.
Note, though, that for 2018, the standard deductions were increased significantly to $12,000 single/MFS, $18,000 head of household and $24,000 joint plus additions for being over 65 and/or blind. Therefore, your itemized deductions would need to add up to more than the standard deduction in order to benefit your return. If you still want to enter your mortgage interest and property tax, take the steps below and you will be asked to upgrade to TurboTax Deluxe.
https://ttlc.intuit.com/replies/4793767
More information on the Free Edition of TurboTax:
https://ttlc.intuit.com/replies/3334660
