There is no separate "capital gains tax." When you sell something at a profit, you have to pay income tax on the profit. "Gain" is another word for profit.
You said you sold land for $87,000, but you did not say how you acquired the land, or how much you paid for it if you bought it. So I don't know if you had a profit or a loss. If you made a profit you have to pay income tax on the profit or gain. Your age makes no difference. You only pay tax on the profit from the sale, not the full amount that you sold the land for. If you bought the land, your profit is basically the selling price minus what you originally paid for it.
If you sell your main home you can avoid paying tax on part or all of the profit if you meet certain requirements. But if you sold land that you owned for personal use, but it was not your main home, you have to pay income tax on the profit from the sale.
If you owned the land for more than a year before you sold it, your profit is a long-term capital gain. If your total income, including the long-term capital gain, is low enough, the tax rate on part or all of the long-term gain might be 0%, which means that you do not pay any tax on the part of the gain that is taxed at the 0% rate.
If you inherited the land, the gain is treated as long-term no matter how long you actually owned it. Your profit or gain in most cases is the selling price minus the fair market value on the date of death of the person that you inherited it from.
