They train apprentices. Mentors are like trainers.
They both Mentor new Supervisors, but the Teen Mentor will usually only have teen Proteges.
This depends upon what type of mentor you are aiming to be. Certain types of mentors may require certification, such as corporate mentors or church mentors. It depends on where and who you are...
A mentor is someone who teaches, helps, or guides you through something.
The person being mentored is called a mentee.