Don't know what I want to do after high school

I am a 16 year old sophomore and have no idea what I want to do as a career or what I want to major in.
I know that it’s okay to be undecided, but aren’t your college plans supposed to determine what classes you should be taking in high school? All of my friends have specific career ideas and are already working towards it (one’s interested in biology, so she’s taking ap bio and taking anatomy next year, another one wants to go into the medical field so she’s taking ap psych, anatomy, etc.)
I’m afraid that when I DO decide what I want to do, I’ll realize that I haven’t done enough throughout high school to pursue that topic in college and that it’ll affect my being accepted.
I do know that I am more inclined to humanities rather than STEM subjects. Some categories that interest me are : English, History, Social Sciences(international relations, sociology, anthropology), Natural Resources and Conservation, Visual and Performing Arts (I like theatre and orchestra so maybe directing, producing, writing?)
I just hope I’m stressing about nothing, but I would like some guidance in narrowing down my options. What can I do to prepare? Thanks!

You are stressing for nothing :).

Focus on your core courses in high school. 4 years of english, history, math, science (bio, chem, physics, and one of those AP), and foreign language. That’s all colleges care about. They don’t expect you to specialize in high school.

For your electives, take what interests you now.

You won’t close any doors if you take the cores all through HS.

Many, many people don’t know what they want to do until much later and the majority of college students change their major at least once.

Relax. Breathe. It is perfectly fine to be undecided. Most colleges do not require students to declare a major until the end of sophomore/start of junior year which is 4 years away. And between now and then I would predict that a number of your HS friends will change their ideas of what they want to do.

In HS you don’t need to be working towards a specific college major or career. HS is not the time to specialize academically – what you want to do is take a well rounded curriculum that (probably) includes 4 years of math, science, social studies, English and foreign language.

It sounds like you have some sense of where your interests and aptitudes lie. Pursue your interests through coursework and your ECs when possible. Let HS (and college) be time of growth and learning. You will figure out your path in due time.