How to get a summer makeover?

In 1 and a half weeks I have my summer holiday and I want to have a makeover ( I got 2 months btw) I'm 14 and not popular at skl at all every1 thinks I'm fat, ugly and stupud and I want to show them I'm not so what I want to do first is lose weight being honest I wanna lose about 15-20 kg. (I know I'm fat) and give me ideas how I'm going to my home (another country) with my family and meeting my actual friends also I want to change my look I was thinking of getting brown highlights in my dark brown/ black hair, I need to be more confident as well and be better and more hardworking (I come from a diff. Country so every1 thinks I'm very stupid) so give me ideas if u got something else, and what do ya think of the highlight idea and how can I lose weight. Best answer gets 10 points so plzzzz help me :) x soz bout asking this again, just want more answers xxx