A lot of these questions are really concerning two things: don't let others tell you what to do (don't use their benchmark as the be all end all) and to consider what is something you can live with long term (so don't just focus on money and status).
That being said, it's okay not to know. I went to college for social work and now I'm working in data. I know at 18 I would not have been interested in data and had the drive to complete the major - I had loftier goals. But then I found data and how I could influence a company toward helping people using their own data and I still use my social work knowledge to not make robot decisions.
If you don't know what you want to do, I found volunteering always give myself meaning. But you can get similar flavor from jobs via back door jobs (despite its name, it is not being a pro bottom)