How can an introverted and quiet new grad starting their early career do well in big 4/consulting?

I’m very introverted, and usually appear as cold and timid to strangers. In my retail part-time job, the only feedback I’ve ever gotten before is to talk more with the customers. Growing up in school, the feedback my parents receive from my teachers is also the same (that I’m too quiet).

Moreover, I’m also the first in my family to enter the corporate workforce and I had an awfully rough time in my last internship because I didn’t know about the unspoken corporate rules. I didn’t get a return offer NOT because I didn’t do tasks assigned of me or that I was difficult to work with, but because I wasn’t able to fit in with the “team culture” and didn’t kiss my boss’s ass. It was an awful experience but long story short, my prev company had a thing with hiring kids through nepotism and none of the white frat boys or sorority girls would talk to me (I’m also a minority), and I was always excluded by them and my manager.

Anyways that’s in the past, and I want to learn to play the game and be able to work in this industry. I’ve had so many managers, teachers and family members who have doubted me because I’m too “shy”. So does anyone have any advice