My advice to you is simple: work hard in school and enjoy college. If you do those things, and have a strong desire to be a physician then things will fall into place. Try to get off to the best possible start this fall as this will set the tone. The best way to do that is to have short-term goals like doing well on a particular exam, or studying a few hours each day.
I knew quite a few people in undergrad that spent ridiculous hours in the library studying and never went to a college party, played pick-up basketball, or wasted an afternoon watching b-rate movies and playing video games. Don't miss out on that stuff--you'll have those buddies forever. College is an awesome experience. Quite frankly, even with only a year left of medical school I would trade places with you in a heartbeat, despite the fact that you are going to BC (I'm an ND alum)!

I agree with HawkIrish, work hard, but don't forget to have fun. Little of what you do in undergrad is going to get you into med school. But you do need something to get in, so don't totally slack. But have fun. Keep in mind that you're looking into ortho as a career, not a life. You need to have a social life so that you can be a person. I look back on undergrad as one of the funnest times in my life, and hopefully you'll be able to do the same in 8 years.