Why should anyone choose Harvard over Yale

Yale or Harvard? What is better?

Hi, I'm now in the 10th grade (G8) and I'm slowly starting to think about my future. I would like to study medicine at a university in the USA like Yale, Harvard etc. (Which is the best?)

I have already read about it on the Internet, but I would like to hear from you what you have to bring with you in order to be taken there. Sure, I would have to take the TOEFL, SAT and ACT tests and have very good school grades. But how is it otherwise, I've read that you have to get involved somehow (voluntary work, etc.), but how much of this work and internships do you actually have to do? And then you should be good at sports or be able to play an instrument well. How exactly do they judge that, how good do you have to be? I play the piano well, I would like to (again) start other sports in the near future, which sports are the most popular? Please give me proper and not stupid answers, I want to do everything for it and prepare myself for my future now and not later think 'oh would I have done this and that'. I know these universities are extremely expensive, but you don't have to worry about that.

In short: What should you bring with you to study at such a university, what is particularly popular (sport, work, internships), how is the application process (how much time do you need for all the tests and the application)?

Sorry for the long text, but thanks in advance for helpful answers! :)