Your basis for inherited property would generally be the fair market value on the date of the decedent's death and your capital gain would be the difference between that basis and your selling price (i.e., if you sold it for more than your basis you would have a capital gain).

Regardless of how long you held the property, any gain would be long-term since the holding period for property acquired via inheritance is automatically long-term (i.e., long-term capital gain tax rates apply).

If you made the home your primary residence, you could exclude gain on the sale of $250,000 ($500,000 if married filing jointly) provided you owned and used the home as your primary residence for at least two out of the past five years leading up to the sale.

https://www.irs.gov/publications/p523#en_US_2019_publink10008938