You will report the sale as follows:
To enter your Land sold
Click on Federal Taxes
Click on Wages and Income
Click on I'll choose what I work on
Scroll down to Investments
On Stocks, Bonds, Other, click the start or update button
Chose Other and report the land sold.
The cost is what you paid for the land, plus closing costs (when bought) plus improvements made.
The sales price is what you sold it for. You will also enter the sales expenses which would be closing costs and other costs you may have incurred.
The loan amount does not go into the cost or sale of the land in computing the gain or loss.