Looking for advice as a pre-college student interested in IB

Hey all, I'm new to this site and have already found a wealth of info in regards to my interests. Though I know it's way too early and I'm far too inexperienced and uneducated to be giving an ultimatum on what career I want to pursue, I think individual input and advice on my situation from some people in the IB industry would definitely help, as I'm interested in mergers and acquisitions. Essentially, I'd like any tips or help anyone could give and things you wish you did/didn't do leading up to entering employment.

A little background: I'm a senior about to graduate, and I'll be attending Cornell; As of now, my major is ILR, although I might attempt to transfer into AEM (business) after first semester; The high school I'm graduating from is private, and is known for having an extremely tight and extensive, borderline cultish, alumni network, which helps.