What are some good stores teenage girls shop at?

im 13 and i live near the mall...and im a female...and all the popular girls in school dress really nice...but i dont...:( and i want to know some good stores i nthe mall to shop at..and what to look for!! i have really long legs and when i wear the same thigs as my friend i feel they look better cuzz i look like a twig and they have short legs and all the guys compliment them...but yeah any tips on clothing?