How to grow up mentally?

I’m in my early 20s. My batchmates started to run with the torch already! And here I’m still thinking that I’m a teen and I just finished Schooling and I have more time to grow up. Even though I achieved a milestone which many in my batch considers a sign of adulthood, I just feel like a schoolboy with no real world knowledge. People around me talk and discuss politics, movies, travel, spending, finance, investments, career, etc… like fully grown adults. I just remain idle, hoping that someone will give me instructions on what to do, how to do and someone will teach me dedicatedly ( even though I know nothing aforesaid will happen, I can’t bring myself into the reality). I know this is what’s gonna happen but I can’t make myself prepare for it or push myself to prepare for it. I feel like my mental growth has just stagnated since Covid times…Hence, I think myself a slow learner, below average student, only a text book worm. I’m ashamed to admit that I’m a school topper. I don’t have any skills that add value to me or anyone… I just feel like going without knowing the direction, without knowing what’s the destination or even without knowing what’s the purpose of all these!