I bought a house in September/2020 and I fully paid it. Where should I report that ?

[DoninGA]

Purchasing a personal residence is not reported on a tax return.  If you do not have a mortgage then there is no mortgage interest to deduct.  Nor mortgage insurance or points paid for the original loan.

You can only deduct the property taxes paid in 2020 as an itemized deduction on Schedule A.

[xmasbaby0]

There is nothing to enter about purchasing a house unless you have mortgage interest,  loan origination points, private mortgage insurance or property taxes paid in 2020.  Sound like the only thing you might have to enter would be property tax if you paid in 2020.

Go to Federal> Deductions and Credits> Your Home to enter mortgage interest, property taxes, private mortgage insurance (PMI) and loan origination fees (“points”) that you paid in 2020.

[Opus 17]

You can deduct property taxes that you paid for the period that you owned the property, even if you did not pay them directly to the taxing authority. For example, suppose property taxes are assessed in January and due February 15 in your state.  Your seller paid all the 2020 taxes in February. When you closed on the house in September, you paid the seller a credit for property taxes that corresponded to the end of 2020 when you were the owner of the property, That the seller had pre-paid at the beginning of the year. You can claim a property tax deduction for that amount as if you paid it directly to the government.