Macbook Air no sound, or lock.

I Dropped my macbook air yesterday from the couch, and now it's running extremely slow along with a loud fan noise as soon as it turns on. Another issue is that the sound is stuck on mute and shows a "no output devices found" message. The brightness keys dont seem to function but can be controlled manually through preferences. One more issue that is really bugging me is that my laptop stopped locking when i close the clamshell. Anyone know what i should do? and what kind of repair it needs?