Nowadays, all you have to do is google search "high school" and a bunch of articles will come up all centered around the same idea: fear of missing out, or "fomo."
Common themes are articles titled "Dear Seniors," in which the author goes on to explain why it is necessary that seniors take advantage of every single thing possible in their last year, or just general articles on why it is so important to be involved in high school or else you will regret not doing more.
While participating is always a good thing, I don't think this idea of "fomo" in your high school years should be so heavily warned about. I for one, was not involved in every club and organization on campus, and I don't regret that at all.
High school is like a mini college for some.
If you were anything like me in high school, I loaded myself up with AP and honor level classes, and my high school schedule was very similar to my college schedule now. I would go to classes between 8-5 (except now my classes have long breaks in between!), do homework, sleep, and then repeat.
When you're a high-schooler taking rigorous classes (some were even harder than my now college classes-i.e AP Physics) you want any free time you can spare to just relax. The last thing on your mind is making that pep rally after class or joining the high school band.
Some of us are just introverted - and that's ok.
I don't really like those articles pressuring high schoolers to get involved in all they can because I don't think it is applicable to everyone. It is easy to tell an extrovert to go be social - that is their strong suit.
However, when you tell an introvert to go get involved in anything they can and attend all social events, you almost have sent them into a panic! I never really attended high school dances except for prom- and even when I went to prom I felt out of place and realized not going to previous dances was a good choice for me.
Do whatever your heart desires.
Moral of the story is that you really just have to do what you want. Don't go get involved in three clubs and four sports based on what others tell you because you feel pressured you'll have regrets down the road, and don't drop all extracurricular activities you are involved in because you decided to listen to someone like me.
Find a good medium and roll with it. In the end, make sure you look back and say "I have no regrets" as in those moments, you were doing whatever made you happy.