How do i flip my life around?

im a 15 year old girl and i want to become..idk...healthy? im skinny but i have no muscles. i want to become tone. id like to eat healthier too. i also have black (unevenly layered) hair with side swept bangs. what would you suggest for a highlight (or low light but my hair is super black)? i also want to make money to buy new clothes at forever 21 and get pedicures and manicures. but i have a problem with saving money so any suggestions?