You can't just have the clothes, you have to listen to the music and have the personality... or else you'll be called a fake.
For starters, start listening to the music. Asking Alexandria, A Skylit Drive, The Devil Wears Prada, I See Stars, blessthefall, A Day To Remember, Bring Me The Horizon, Suicide Silence, Iwrestledabearonce, Blood On The Dance Floor, Bullet For My Valentine, Attack Attack!, these are a few that I love... I recommend you try listening to them.
Personality: We're not all depressed like people generally stereotype. Although I am... for personal reasons. Still everyday people, pretty much the same personalities as everyone else.
Clothes: Converse, Vans, Skinny Jeans, Band T-shirts from concerts, Graphic Tees, Tons of bracelets, necklaces, Hello Kitty, these are generally things I enjoy. Brighter clothes are generally "scene", darker clothes are generally "emo." It helps to have the hair and dark eye makeup as well.
There's more to it than just looks. Hot Topic has all the clothing you'll need.
well, by your name [soccergirl], i would guess that you are active. i would just buy clothes that are comfy and you can use them for everyday and for sports [i.e. basketball shorts]. I myself am very active. i don't worry to much about the brand for sports since it just gets dirty real fast. i do like brand name for when i am not playing sports though. overall, it all depends on your preference and what you feel is comfortable.
ok, hope i helped.