Finance/Accounting/Investment Banking & Corporate Finance online Courses & Certifications

Hello, I was a senior who just graduated high school early by one semester. I am going to a "semi-target" that is well regarded in business programs, especially finance, and located in a big city. I have from January until the end of summer until I start college. I have been accepted with a full ride and into honors program, and I am coming here to ask about the Forum topic title above of the best courses and certifications to do considering my situation. That being said I do have a good budget and ample amount of time on my hands to complete these. My high school did not offer a whole lot of financial literacy courses during my years, so I would say I am a beginner in that space. I was looking for suggestions on what I should do in order to put myself from "zero to hero" in learning all things necessary for future IB opportunities and getting into this space. For example, i was wondering if someone could give some advice or roadmap on how I can start learning at a beginner level and work my way up to mastery, of all things needed to know for IB/Corp Fin, like the accounting/finance/modeling/excel, etc. I have heard alot about certain websites, but I am sorta confused on how I should start learning and create a path/roadmap to go from beginner to master. Thanks for responses and insight.