Stop thinking about what a bunch of people in a room reviewing an application are going to think about or care about 4+ years from now. Focus on figuring out your life, your interests and your development. The vast majority of people applying to medical school figured this out as they went along. You have the advantage of foresight and early interest. Don't handicap yourself by getting tunnel vision. You are hurting yourself long term far more than you are helping.
#1 Shadowing - Yes, post-high school students shadow. It may be a tad more difficult to find people willing to take you on, but certainly should be doable in most places. This is your starting point. You need to come into it with a very critical mind. You need to not be afraid to say, "Wow, this sucks, I don't want to do this." By the same token, you want to use your exposure to figure out what you like/dislike about medicine so you can articulate it to others, either when looking for new positions or when actually applying.
#2 Have you already been accepted to undergrad? If no, then you really need to focus on that before anything else. If yes, then you should explore what opportunities your undergrad will afford you in this pursuit. Be wary of 'pre-med' advisers as they are very hit or miss when it comes to their information. But, you want to know about pre-med clubs/frats, associated hospitals/shadowing opportunities, big research labs, etc. While everyone values a certain element of independence, the concept of "economy of effort" is incredibly important. Most undergrads send dozens (or hundreds) of people to medical school every year. You do not need to re-invent the wheel.
#3 Piano sounds like a good hobby. Keep doing it.
