Goths tend to wear a lot of black, eyeliner, fishnets, striped tights, and corsets. Search the internet for images of goths to get some ideas about what kinds of clothing you should wear.
to dress goth you usually wear black and some other color accent. boots,tripp pants,chains on pants,baggy clothes,black hair, heavy eye makeup,corsetted dresses.
From a previous goth: get real with it. Emo strikes gothic people as surface and fake. Sure, dress in black, but learn the real undercurrents of the movement. Read the books and poetry, think about death and how life can be shallow in its advance towards it. Stop shopping at Hot Topic.