Interested in Business World

Hey everyone, I'm currently going into my first year of University in Canada. I do not have a firm idea of what I want to do when I finish school, so I decided to take a route that keeps as many routes as possible open. I am interesting in Law, Banking, and Medicine.

I am at Queen's University, which is one of the top universities in the country when it comes to business. Many recruiters come to the school to recruit (from both U.S and Canada), but they mainly come for students in the commerce program. I did not want to take the commerce program because it is a specialized program that completely shuts the medicine route off for me. Instead, I am majoring in Drug Development and Human Toxicology and getting a business certificate (basically a minor in business)

My question to you guys is, assuming I can nail a very high (3.8+) in this program in both the major and minor courses I take, how can I make the jump into investment banking. At the current moment, I'm not even sure I want to get into investment banking, but if that is where I end up being interested in going into 4 years from now, then so be it. As a student with a major in Drug Development and a minor in Business, my education can definitely be applicable to the investment banking world, but how can I go about to increase my chances at nailing a good job after graduation aside from high grades? What sort of things should I get involved with (not only to pad my resumes for job applications, but obviously for me to decide if this career path is right for me)? I've been told that certain science topics (drug development being one of them) is viewed favorably in the investment banking world, so I know I'm not a lost cause.

PS: I know some of you will say I am too young to be thinking about this, but if I don't think about this now, I don't want to end up thinking about it when it is too late, when I cannot get an internship anymore, didn't do required things during my undergrad, etc. Currently it is summer and I have nothing to do but ponder about my unknown future.

Thank you very much for any advice! And again, before you tell me I'm probably going to change my career preference many times in the future, yes, I admit that is a possibility, but I want to research this potential career pathway right now. After all, if this is the area I want to go into, I will literally be starting work in 4 years which is not too far off...