Okay, somewhere in the next four years, you may want to do ECs that are lumped into these categories...
-Volunteer-Clinical (volunteering in a medical setting, like at a hospital, nursing home, etc, any experience in the health field)
-Volunteer-Non-Clinical (volunteering in some area not necessarily health related... it shows your altruistic side!)
-Research (not to be worried about your freshman year, although some SDN overachievers probably started freshman year...but the vast majority dont)
-Work Experience (if you need to, if not, skip this)
-Extracirriculars (things that interest YOU! and that you will naturally ENJOY! Any clubs? Intramural sports? Artistic endeavors?)
Also, during a summer or a break, you want to shadow doctors to get an idea of what the profression is about.
I hope it kind of helped!