You sound like a pretty normal teenager to me. You’re just being open about your anxieties while everyone else keeps them hidden.
No one gives us an instruction book about life when we’re born. Seems like someone should, doesn’t it? We get one with a new car, so why not with a new life? Kind of unfair. Too bad that things are that way. So, we just have to figure it out for ourselves along the way. It’s a challenge!