I'd post on the Harvard reddit for some direct comments.

In my perspective: You have little to worry about. The campus is pretty beautiful- the ideal combo of a historic campus with renovated areas and integration with a bustling college town (and quick access to Boston). There is a strong residential emphasis, and for the most part, people at Harvard are humble, friendly, and deeply inspiring. You'll be learning as much from your engagement with them as you do with your academic experiences. The world truly is your oyster at Harvard- you could study just about anything in close mentorship with some of the most brilliant minds in the world. Professors take undergraduate engagement seriously if you put in the effort to connect. There is no shortage of interesting and fun events, speaker series, and the like. It's a truly distinctive experience- congrats on your acceptance!

Some of the downsides are: 1) some clubs and opportunities can be extremely competitive. Keep an open mind for them and don't hesitate to start your own thing if you see a niche for it. 2) there's definitely a bit of a stress culture. Harvard students have this expectation they have to constantly be busy and engaged. How you choose to participate in that is completely up to you. Harvard's mental health resources are pretty good relative to other schools, so if you're burned out, please get the help you need.