You may choose a contractor or you may yourself repair the land while you stay in the same place. Both have their pros and cons. While having a contractor will be a fast process, it may lessen your profit. You may choose to repair yourself if you think you will do it fast enough or you may move in and live in the same place.

You may choose to buy any land, and then hold it, or repair it. When the price of the property increases, you may sell it.
If you stay for over 2 years, you will save real estate tax as per the tax laws.

Alternatively, you may buy land online that is usually much cheaper, and then sell it, or repair it and then sell it.
Measure pros and cons of everything before you proceed.