i'm learning metallica - nothng else matters i've found a note that i am unfamiluar with it displays (x) how am i men't to play this note

Are you looking at a chord notation that looks like it's on a guitar neck and that shows where to put your fingertips to make the chord? If so, the x could be behind the nut (place where the strings rest in slots after they leave the tuning machines (tuning knobs). If that's so then that means you don't play that string in that particular chord.

GuitarZen