You'll report the land sale under Wages & Income / Investment Income / Stocks, Mutual Funds, Bonds, Other. On the next screen, click +Add Sale. You'll choose "Land" for the type of investment you sold (see screenshot below).
You will not need to enter the house purchase on your return unless it is being used as a rental property, in which case it would be entered under Rentals, Royalties, and Farm in the Wages & Income section of the return.
