Back to School Stores and Outfits?

Okay I'm starting H.S on August 23 and I just want to know what style I should start wearing and where I should start shopping for clothes and accessories. I usually shop at aeropostale, forever 21, rue 21, Macy's, papaya( mall store), delias, pac sun, image( sometimes), and buh-ya-kai(mall store, specializes in -lifting jeans!!LOL), bloom(mall store). Also I want to dye my hair from dark brown( almost black looking) to chocolate brown what color should I get to achieve that color??? Thanks your opinion means alot..... changing my image next year