It is very common problem as camera mishandling can happen with anyone. You may drop your camera by mistake in river, Sea beach side, pool, Water Park or simply in water will damage your camera.
To fix this problem you need to leave the camera to get it completely dry. It depends upon how much water get inside, the camera may or may not get repaired and recover. First thing you have to remember is that “do not Turn ON your camera”. After this leave your camera to get dry completely. You may open the camera compartment such as take out battery or any other component and leave them alone. Once you are sure that camera has got dried completely assemble the compartment and Turn it ON to avoid the damage. The camera may need new memory card or battery.