I'm a high school student and I need to select what I need to study at university soon, which will determine what job I do afterwards.

I have a list of about 20 fields that came to my mind and which I may consider, ranging from med and biotech, to psychology and therapy, to data scientists and coding, to social workers. How do I eliminate options so I can decide what I want to do?

After googling I've made a document with answers to questions like the type of lifestyle I want, what I value, what my interests, skills and passions are etc. It still feels very vague. I feel I don't know myself enough to decide what career I want to go into. Skills can be learned and I feel I could manage doing anything if I had to (although ofc I'm less inclined to some). Interests ebb and flow, they aren't reliable.

Any advice?

Also if I could chat with someone to discuss this kind of stuff I'd really appreciate that.