Water entering your camera can leave smudges on the interior of your lens that you can not clean. Do not attempt to use a hair dryer to dry your camera. You can try placing your camera in a bag of rice to see if this resolves your problem.
The speaker may simply be partially obscured by dust or debris. Try blowing the speaker with compressed air to remove any blockages. If this does not resolve your issue, refer to the audio section of the troubleshooting page.
This could simply be the result of damage or debris on the lens and have nothing to do with the LCD screen. Visit the troubleshooting guide for help determining your exact issue. If the problem is definitely the LCD screen, you may need to replace it. Refer to the screen replacement guide.