Why do you not have a 1098? Do you have a seller-financed loan or a private loan? If so, post some details about the type of loan and we will tell you how to enter it.
If your loan is from a bank, credit union, or other commercial lender, ask them for a copy of your 1098. If the interest you paid was less than $600 for the year, they are not required to issue a Form 1098, but they can tell you how much interest you paid, and how much real estate tax if that was included in your payments.