I want to change my image for next school year, I will be a junior?

I wanna go from the nice girl that's always friendly to someone who everyone will just leave alone! I love the color black and skinny jeans and stuff but how do I get people to take me seriously. I basically want the personality of Jade West on Victorious or Samantha Puckett on i Carly or Damon Salvatore on Vampire Diaries. I'm changing for me and no one else, I can't dye my hair and I don't wear any make up and don't plan on wearing any so what else can I do?