What is the process of becoming an investment banker?

I am a high school student with average grades. I am currently in 11th grade. My grades so far have not been too bad. My current lowest mark in a university/mixed level course is a 70% (in Biology, and I am never taking it again) and my highest is an 81% in Chemistry (definitely not doing Organic Chemistry next year, never). I live in Canada so a 70% is a B and an 81% is an A. My current semester average is 70.5%.
I aspire to be an investment banker. I am quite introverted but I can tolerate being around other people. I truly enjoy business and finance (scored 90% in Business) and I am quite enticed by economics (which was the sole reason why I did not fail 9th grade Geography).
I am going to apply to University of Western Ontario/Western University. Next year I am doing all three Mathematics classes (I am not too bad arithmetically although I do struggle with Language Arts) with the "at least" six university or mixed courses in my timetable, all easy courses like Accounting and International Business to boost my average.
My major is undecided. I have asked many adults "what to do," explored different forums, but a lot of the content seems brand new to me.
What is the process of becoming an investment banker?
I really do not know what to major in when I reach university. I have been contemplating Actuarial Science but the amount of mathematical courses terrify me.
How difficult is it to get into Richard Ivey? If I apply directly from high school, would they weigh my 11th grade scores too? Or only my 12th grade ones? Should I even go for the Masters of Business Administration or should I become a Chartered Financial Analyst instead? There are many different articles stating "CFAs are useless" or the "MBA is overpriced and useless."
My intention is to make plenty of money. My parents are not very supportive of me going into investment banking because they say I will be on the street with null job opportunities. Everyone around me is quite pessimistic about my career aspiration.
(Forgive me if the tags seem irrelevant, I want an urgent answer to this question because I am troubled by what to do with my life and I have to decide on my 12th grade classes soon. I like science but I find the amount of projects they give us to be overwhelming and stupid, especially f*cking coloring assignments and model construction)
Please do not throw monkey shit at me.