Where do I report sold stock?

You enter the investment sale in the Wages and Income section of TurboTax, then Investments Sales, then Stocks, cryptocurrency, Mutual Funds, Bonds, etc... 

For the cost basis upon sale of a security given to you, if the fair market value (FMV) of the gift was less than the donor's basis, you would enter the cost basis that the donor had when you took possession of it, unless you sold it at a loss, in which case you would use the fair market value when you took possession of it. If the cost basis was equal to or less than the fair market value when you took possession of it, you would enter the donor's cost basis as your basis upon sale. 

You can learn more here about the cost basis of gifts.