It may be a great idea to go to work as an apprentice/ or an internship with a home builder over the summer so you can get hands on experience. Search your area for small, Owner Operated construction firms as well since that Owner has probably been where you are and advanced to where you want to be.
Put your concepts on paper. Writing ideas down is the first step in making a thought a tangible. Next do a business plan. Check out a site like Business Planner.
Mia recommends the following next steps: