And hopefully the card wil fit into your case. Did you check that before buying?
Oh and btw, after u plugged in the card u have to find a free power cable from the PSU inside the case to give the GPU some extra power. U fit that cable into a little slot on the side, near the short end of the GPU (there might be 2 of these slots and 2 cables needed cos it's a powerful card, I can't remember).