You sound fine as an applicant, but you will need shadowing. I'm not sure exactly how everyone finds doctors to shadow, there is department here at my school that helps to set up students interested in medicine with shadowing experience (not just doctors, but PAs, nurse, etc.) Maybe ask your adviser if there is anything like that in your area.
The shadowing is important because medical school's want to make sure that you actually want to be a doctor, not just someone who is really good at science.
Also, no, a C in your freshman year is not going to make a difference, especially if you can continue the upward trend with your grades.