Entrepreneurship is a contact sport. It cannot be learned from a book or in a classroom. The skills which underlie entrepreneurship are largely learned first-hand, through trial and error.
However, you do not need to start a business to begin exercising your entrepreneurial muscles. There are a number of tasks you can perform that will allow you to train in the art of entrepreneurship while you are in school or working at a large organization.
http://www.forbes.com/sites/johngreathouse/2016/04/12/7-ways-to-practice-entrepreneurship-without-starting-a-venture/#2c43b3542fee
