Do whatever you want! You still have plenty of time to dedicate your summers to research, clinical volunteering, etc.
My advice -- explore your interests! Test your interest in medicine by trying something that seems interesting to you. An important part of preparing for medicine is testing your interests with real experiences in those fields. Look for a volunteer position at a local hospital, get an EMT-basic certification, or take a class to get your premed requirements out of the way (and open up room for fun classes!).