I want the players face to change mid game but it won't work. i put my script in the workspace.
wait(3) game.Players.LocalPlayer.Character.Head.face.Texture = "rbxassetid://1612075567"
You cannot access the Local Player through the workspace, nor can you access the Local Player with a Server Script unless you're sending a parameter or argument through firing an event.
If this is a Local Script you're writing this in, I suggest you move it to something like StarterPlayer or StarterPack. (StarterGUI works as well.)
If this is a Server Script, rewrite it in a Local, and move it to one of the designated areas above.
Best of luck in your future endeavors!