Having an education for any trade is the best investment you can make in you and future company. (this is from a person that dind't finish college)
Maybe hort. is no the thing for you but at your age I would reconsider that if you are looking in getting into this field.
You can check out ICPI.org and take that course to begin with, then
http://www.ncma.org/meet/edu.html
Also try to take course for business management, sales and marketing, budgeting and estimating.
Good luck