Thanks for such brilliant question. It's a matter of importance to find a mentor whose life and achievements are in line with your prospects and field cause it'll help to direct and channel you better towards reaching your goals, like myself as a Human Relation expert i have mentors like Dale Carnegie and other human relation expert like myself whose biography and books i have read and they have given me a-lot of insight on how to handle people and my relationship with them.
So first of all in finding a mentor; you have to find someone whose life appeals to you and who falls in your line of interest, goals, field of expertise or moral standard in general. Then research about the person, ask questions and gather as much information as you can about the individual, if he or she is pretty much alive or active you can try reaching out to the person as that would be another step ahead of the game... Hit me up for further insights and direction... Have a blissful weekend and Remain Blessed.