Valuable skills for an IB career? + Strategies to optimise college to for IB jobs at BB banks?

Recently was accepted to Dartmouth College for econs (undergrad). Am super stoked, but am finishing up military service and happen to have a fair amount of time on my hands before I matriculate next fall. What skills would put myself in the position to both succeed in university and then eventually (hopefully) in an IB position? Building on that, I understand it’s far away, but what are some good things to do once I’m at Dartmouth to maximise my chances of landing an IB job? (Internships, activities etc) Hopefully I don’t seem like a tryhard, just have a lot of time on my hands and am trying to plan ahead.