1) your applications are due by halfway through sophomore year. On top of everything else you're doing, I wouldn't expect you to have the same shadowing hours that a 4 year student would. That said, you have a little over a year so getting at least 50 isn't impossible, esp if you do it next summer.
2) that said, you still need to be able to answer "why medicine" esp for a program that encourages non-science majors. So if you have zero exposure to medicine or the day-to-day of a physician, your answer may be seen as insincere.
3) Shadowing isn't necessary for any application as long as you have significant clinical exposure. I got in with none, but had over 1000+ hours of clinical volunteering. And no physician LOR.
4) Teenagers have a prevalence of being irrational and impatient. All this does is make you neurotic and increase your risk for burnout. Mosey on over to hSDN an look at that stress nightmare. For example: