Hello, a Korean-American (studying in Korea) looking to get into IB!

My major is International Business and I wanted to go into marketing but recent events made me decide to switch over to IB. Problem is, I'm in my senior year. I have taken several classes related to finance and am currently drowning myself in highly recommended literature such as the Intelligent Investor. However, I am not entirely sure what exactly I need to study to get a good internship. My GPA is around 3.9 and I have the drive to work my butt off to achieve my goal. The only issue is that I need someone to point me in the right direction. I'm hoping someone here can recommend some books (or even textbooks) and give me some good advice so that I can at least know I'm heading in the right direction. Thanks!