where can i buy and for how much money, can i get a cover or something to go over my camera (if theres such thing) so i can take it under water without having to worry, im going to the florida keys and i would like to take pics while scuba diving.

Not sure since you didn't list the model… but Adorama and B&H have extensive amounts of prodcuts in inventory.
Look there are many suppliers, your first stop would be to work out the depth you will be using the camera at, below 15 meters you will need lights. Once you establish this then you can look into the camera, some brands like technika make ready to use cameras with housings and light systems, also teckhnika. You should also look at the off the shelf housings that many digital camera manufacturers make (cannon etc) they are usually good to use down to 20 meters.

I personally use Wills housings but they are a lot more costly as they are a professional housing.
Good luck!