Student or Learner
The new employee is looking to/for the supervisor for instructions.
Which preposition should I use?
"To." It means that the new employee is relying on the supervisor to provide the proper instruction.
Looking "for" the instructor implies that the new employee is temporarily unable to physically locate him (or her). In order to properly use "for" in this example you'd have to say something like "The new employee was looking for the supervisor because he needed instructions" or "The new employee was looking for the supervisor in order to receive instructions".