Congrats on your admission! From what I understand , Lean Gap should be a good productive use of your time if you want to start a business. It is a rather new company. It has only been around 3 or 4 years, so doesn’t have the reputation of a MIT Launch or Endevvr (which for some unknown reason suddenly closed for this year). Lean Gap was started by the young, remarkable Eddy Zhong who also has some MIT guys on his staff. They should be able to coach, inspire and teach you a lot about a start up. Good Luck.
By the way, here’s an article about Eddy Zhong.
http://www.betaboston.com/news/2015/03/17/■■■■■■■-encourages-high-schoolers-to-unlock-their-entrepreneurial-potential/