How should i change up my hair?

i dont want a scene or emo haircut. im a total prep, nerd, teachers pet, but m dieting and hoping to lose 20-30 lbs so i want to totally change my look by doing something different to my hair, currently i have curly medium length dark brown hair and side bangs. so what should i do? i dont think i want to cut it shorter though, i want to grow it out. so i was thinking more like diff color or bangs, etc etc. im going into my freshman yr in high school so i figured fresh start!