Advice on subjects to explore pre-transition to business (from science?)

I am transitioning from the pre-med track to the business field at another institution, and I am extremely intimidated by the ‘‘other side’’ of my field leap: I am very much used to students who do research, hospital work and charity work, but I know next to nothing about the world of business students that are extremely involved in their academic and professional life such as case competitions, stock pitches and networking clubs. Nevertheless, I believe that this is the world in which I belong, and I am set on making the switch!

Any recommendations with regards to subjects to learn, skills to self-teach myself, events to partake in? I am currently taking a basic online course in Accounting and Finance, which isn’t much, but I would am hoping to become proficient enough to get an internship as perhaps analyst or accounting assistant for a small company during the summer pre-transition.

Would love to hear from business students, particularly those who also made a switch into the field!