You owe tax on capital gains. A capital gain is when you sell property for more than your cost basis. In the case of inherited property, your cost basis is the fair market value on the day the prior owner died. Assuming you sold the home reasonably close in time to when you inherited it and the value didn't change much, then your cost basis and purchase price are equal, and you don't owe capital gains tax.
If you held the property for a while and the value increased, you might have a taxable gain. On the other hand, if the value decreased, you might have a tax deductible loss. (As long as you never lived in the property as your home, you can treat it as an investment, and you can deduct losses when investments lose money.)
If you received a 1099-S at the closing, you must include it on your tax return, even though you won't have a gain or owe tax. If you did not receive a 1099-S but you have a gain, you also must report it. If you did not receive a 1099-S and you don't have a gain to report, you can ignore the whole thing and leave it off your tax return. (However, if you choose to report the sale you might be able to deduct certain closing costs, and that might allow you to claim a small loss that would be deductible from your other income. See publication 523. https://www.irs.gov/pub/irs-pdf/p523.pdf)
