When I was your age (I'm 36 now) I found the reading list from the Personal MBA guy incredibly useful. The list is 2-3 books in 30 categories from negotiation to communication to basic accounting. These are a list of the things older people wish they'd learnt in school. Things you didn't know were important until it was too late.

https://personalmba.com/best-business-books/

I'd start by reading. That's it. Just reading and thinking.