I don't have all the answers, but here are some things I've found useful. Take what resonates, discard the rest.
For people in their teens
Go deep on things. Pick a few areas that fascinate you and learn them to an unusual depth. You'll figure out what you actually care about faster this way than by sampling everything superficially.
Build things. Don't just consume. Write, code, make, ship. The gap between people who make things and people who don't is enormous.
Find your people online. The internet lets you connect with the most interesting people in any field. This is one of the biggest advantages you have over prior generations. Use it.
Don't follow the default path. The conventional trajectory exists because it works for the average case. If you're reading this, you're probably not the average case.
For people in their twenties
Optimize for learning rate. Early in your career, the speed at which you learn matters more than your title or compensation. Join the team where you'll learn the most.
Work with great people. You become the average of the people you spend the most time with. Choose carefully.
Say yes to asymmetric opportunities. Things where the downside is small but the upside is large. Most of the best things that happen are the result of saying yes to something unexpected.
General
Read broadly. Most of the best ideas come from importing concepts across domains.
Write regularly. Writing clarifies thinking. If you can't explain it clearly, you don't understand it well enough.
Be patient with results but impatient with actions. Good outcomes take time, but you should bias toward action in the short term.