everything on the screen is too big, can't move the menu down to access programs since it is off screen, can only see the lower part of the menu item I want to us and the actors heads are all cut off.
Go to settings, display type and change your display resolution to a different one, maybe 1080p vs HD and see if that helps.
If this is a TV with separate Roku attached...
Also, check your TV itself for a setting that adjusts picture size (could be labeled "zoom", "size", "picture", or something similar). On most modern sets, this can be controlled separately on each input.