I recall the beginning biology and chemistry classes to be about 150 students. However, my S did take some honors sections that had 25 students. After the initial classes the upper level classes got smaller. Not sure if things have changed since back then. You would have to contact the pre-health office about all the premeds getting into med school as I don’t know anything about that. The volunteering, research, shadowing opportunities are all there- it is up to the student to pursue them and secure them. The school will give guidance, but there is no automatic matching for positions.