Driver side door won't close.

 

won't close meaning its misaligned or the latch is not holding the striker screw? see if you can manually set the latch (ie with the door open, move the latch to see if it will stay in the closed position. If not you'd need to open up the door to see what is jambing the latch mechanism. If its misaligned, you'd need to check the hinges to see if bolts are loose and readjust as needed or see if there's damage from an accident or broken/worn pins.