Set Goals
My best advice to a teenager would be to set SMART goals, which means, specific, measurable, attainable, realistic, and timely goals.
I also suggest reading a couple of books…The Power of Now and A New Earth, both written by Eckhart Tolle. Live in the moment…nothing else matters but what you are doing right NOW. If you made a mistake in the past, take responsiblity for it and ask for forgiveness then let it go. There is no need to create a story in your head and relive that mistake over again.
Becky R, got this advise from a coach