None. A lot of managers work their way up from a career of playing, then being coaches, then assistant managers, then managers - this is called "the school of grass". Others do take specific courses in universities, and have only recently begun to garner any respect, with a few of them winning titles.
About 3 years but it would depend on the course you chose.
Play the game, study the game, start at a lower level, take classes in sports science.
they have to study physics and do well in PE
You can be a sports coach after doing this course.
Study
One can study to become a life coach in the United States through the International Coach Federation. The International Coach Federation does training to certify you as a Certified Master Coach and also a Master Professional Coach. The International Coach Federation is the most well known and respected training center currently available.
study of theology
You can study a course at any college, university, community, or otherwise and become certified to be a nurse in the United States of America. You can also take classes online.
You can go to college and study a photography course such as HND and BTec
in truth, you have to study the course to be an ASPCA Officer Get the degree
You don't study to become a soccer player. You practice your skills depending on what position you play. Normally the big clubs in England will send scouts to find the best players around the world. So play for a a club and maybe you will be spotted if your good enough.
Love for the game, knowledge of the game, and determination. The best way to start is to become a teacher and study the game. Coach peewee first, move your way up.