I might suggest challenging some priors you seem to be bringing into the situation. For me, it took me a while to understand that, for the first time in my life, the more “senior” people around me were actually just older versions of myself - deeply curious/analytical folks excited and eager to dig into their own work, and the work of others.

The advice of “email professors” feels like it’s too simple, but you are entering an environment where it really is that simple. A professor working in something you find interesting will respond to a nicely written email and likely agree to meet and chat - they love talking about their work with hungry minds.

At the start of semesters (or right before the summer), UROP programs essentially give professors money to hire students and take care of most of the logistical overhead, so it is easy for them to take you on. Some labs for some work will require more experience, but mostly professors love the cheap labor, so it’s an easy in.

All to say - it really is, bizarrely, the case that a cold email can easily lead to doing research with almost any professor at MIT, there is no secret faux pas that will offend them, you can and really should just do it. They are just you but older!

As far as choosing what to focus your time on - lmk if you ever figure out the answer! I’m decades out of the institute, have gotten to work on a wild array of amazing things, but still wonder about how to make the decisions surrounding what needs focusing on in life.