Which decisions I make today will affect me for my entire life?

I think that the decisions that I make in high school are the most important and will affect me the most in my life. The decisions I make now are crucial to my future because i am very close to becoming a college student. next year i will be in the 12th grade making me a senior which is one step closer to becoming independant and on my own. i have many goals for myself so that i can have a prosperous future and I have to make sure the things I do now are positive things because the decisions I make now will follow me into college which affects my success in college. I believe that any bad decisions that i make now will affect me the most for the rest of my life because for me, being an 11th grader is important and i can't afford to mess things up now.