Mortgage interest on personal use real estate, such as your primary residence or 2nd home is reported on SCH A. There is a $10K cap on the amount of *PERSONAL* mortgage interest you can claim. Additionally, there is a $10K cap on the amount of state and local taxes (SALT) that you can claim. All of this goes on the SCH A.
Now, until the total of all *allowed* itemized deductions on the SCH A exceed your standard deduction, the standard deduction is better for you. The itemized deductions *do* *not* *help* until they exceed your standard deduction.
So if filing joint your standard deduction for 2018 is $24,000. So if your itemized deductions do not exceed that, there is no need for your to itemize at all, since the standard deduction will be the better deduction for you.
