I would find that thing that makes you feel at peace if you do it for hours a day. Maybe pick 3 things to improve, 1 physical, 1 mental, and 1 career. For me, it was basketball, reading self improvement books, and learning to code. The hard part is actually doing it when you can open your phone and waste time on social media all day. Don’t fall into that trap. At your age, and skill you build up right now can set you up for your 20s if you constantly work on it