There are a million "self improvement" cults out there all of which are dangerous rabbit holes to fall down. If it's got a website, a newsletter, a charismatic leader, and a few million outspoken supporters that's probably a sign to steer clear.
In my opinion there's some practices that help:
Seek out and talk to people you respect. Better if you can do this face to face, in real life. Having respected mentors should not stop where parents and school teachers leave off. If you're really stuck socially at this (as so many young people are today), try paying someone like a therapist of coach to get you unstuck.
Read old books. Actual paper books from before 2000 at least. Build up a good knowledge of human psychology, philosophy, politics, the arts and classic literature. Philosophy of human values is a good place to start.