In life, you’ll be given many opportunities to do many things. Some of those things will excite you at first and irritate you later. Some of those things will irritate you at first, and excite you later. But the thing that matters most, is that you pick the right set of things to say yes to, which means learning to say no more often. By consequence of how many things there are to do, it has to be the case that the subset of things you’ll both appreciate, and learn from is smaller than the set of things where one or both of those qualities is missing. If that’s true, it means you need to say no more often than you say yes, because the opportunity cost of doing the wrong thing is too high.
What is the “right” thing to do? I think it depends on your wants and needs. One way to determine what’s right is to pay attention to all the things you’ve done in the past, and assess the similarities between all the good decisions you’ve made. If it was “right” to go to college because you found community and a passion for a particular area, then do more things that enable that kind of outcome to happen. If you look fondly on the nights spent in solitude, because it gave you an opportunity to be introspective, seek out other opportunities to do that deep reflection.
Similarly, when you look back on all the things you regret doing, ask yourself where you went wrong, and try to establish some criteria for what makes a decision bad. Almost all the things I regret doing rhyme with overcommitting when I didn't have the bandwidth and/or doing the kind of thing I know I won't be proud of at the end. Additionally, a good signal for me to know I'm doing the wrong thing, is when my only justification for doing it, is to say I did.
Learning to say no is hard. It's hard for people pleasers like myself who want to make everyone happy. It's hard for anyone who cares about creating a good image of themselves to other people. It's hard because humans are generally terrible at estimating their own capabilities. But the truth is that you're at your best when you've given yourself enough slack to do the things that really matter, and none of the things that don't. And you can't get there by saying yes (too often).
So say no. Turn down that offer for the job you know you weren't going to be happy at. Say no to the friends that invite you out, on the night you planned to watch movies and lay in bed. Say no to the parents who have constantly asked you to live a dream of a life they couldn't. Just say no, and look to see how much life rewards you for it.