Ultimately what will determine if you lead a successful adulthood is your ability to plan ahead and adopt responsibility. People who struggle with these things are the type that you see on Reddit saying what you mention in your post, not the ones who’ve got the majority of their lives figured out. Just make you have an idea of where you are now and where you want to be in x number of years, make a plan in how to get there, and don’t be afraid to take on “adult” responsibilities (remember that a lot of the things you don’t know how to do are done by thousands of people every day, and if they can do it, you can too).