I buy company stock , 1099B states Payer's Name: Nucor Corporation E.M.S.I.P. C/O American Stock Transfer & Trust Company not sure type of investment

there are no brokerage fee's for purchase but I paid a fee when I sold it  ,not sure what type of stock investment it is (ESPP,NQSOor ISObecause I sold some does that mean I have to mail in a Form 8949 ?