Maybe not advice for the 9 year old me.. but certainly as follows:

Don't worry so much - If you spend all your time worrying you will only regret it. Life is short and you have to take advantage of it. Not worry about the consequences.

Have more confidence - I really need to believe in myself more. Past self and present.

DO NOT CUT YOUR HAIR - Yes I did, and I regretted it.

Take more pictures - There's a period of my life where there is no photo record. Kind of sad...

Don't leave your homework to the last minute - because that never works out now, does it?