I would try to get out of the woods as soon as possible. A floating shark roaming through through the forest is creepy and as scary as seeing a shark in the ocean. But if I didn't get out of the forest, I would try to kill it with fire or anything that I had with me. The only thing i wouldn't do is just sit there and wait for the shark to leave. I would be extra careful not to make any noise and also I would be extra careful to not get hurt in the  forest because sharks weaknesses is blood.