Help with scence hair!!asap plz!!?

hello:)im 13,and im scence.i shop at hot topic alot but theres 1 thing im missing....THE HAIR!i hav medium length hair,it light LIGHT brown/dirty blonde,i hav side sweeps to and i straighten my hair like EVERY DAY!but idk what to do with it.i was thinkin light on top but dark dark under neath but idk if that would look good.any ideas??all r welcome:)thank u:)O!and i have many x-tensions:)