By now, you should have chosen a major, established solid study habits and begun to fulfill course requirements for admission. It is also time to begin exploring your interest in a health profession—by working with a practitioner who works in your area of interest, for example.
The spring semester of your sophomore year or either semester of your junior year is a suitable time for an internship experience. You should pick a semester in which you will have sufficient time to devote to it. You want to avoid a semester when you are heavily involved in athletics or performance, and the semester in which you plan to take the admissions test for professional school.