Get your stems unwrapped and wash off the hydroponic gel. Trim the stems at an angle and get them into a clean vase of fresh water to give them a good drink. Remember to remove any excess leaves or foliage below the water line; all the water needs to be going to the stems.
Geberas can bend a bit due to the weight of the head. This can be remedied by reinforcing your gerbera stems with a piece of stick or sturdy wire.
Aside from this, the usual flower care tips apply: change the water every few days and keep your flowers away from direct sunlight, drafts and heat sources.