You should consult with a tax professional in your local area.
See https://taxexperts.naea.org
Regardless, your gain will probably be considered capital gain on this transaction since it appears to be, generally, a one-off.
However, if you wind up classified as a real estate dealer by the IRS, the gain (profit) will not only be considered ordinary income but also income subject to self-employment tax. Some of the factors to be considered are the number and frequency of purchases and sales, your intent, the number and extent of improvements, et al.
