Normally property tax is listed on the 1098 when the property tax is paid through an escrow fund along with the mortgage. If the property tax was paid directly to the city or county, then you will find the amounts on the county auditor website, or check your personal records for a receipt.
The property taxes you paid on the old home you sold, I assume are on the 1098.
The property taxes on the new home are, more than likely, on the closing statement you got when you closed on the purchase of the new home. Take note of the following:
-When you sold the old home, chances are the buyer had to reimburse you a portion of the property taxes. If so, then you have to subtract the reimbursed amount from the property taxes paid, that is shown on your 1098 for the home you sold.