Tail lights wont work ?

All the bulbs are gone or the brake switch is faulty. Mechanical spring switches can be adjusted, but most are electronic these days and will need replacing.

It can be found above the brake pedal. 

You gotta trace the wiring and look for a break in the wire or a plug that came loose.

Also check for loose grounds (a wire that is screwed to the chassis somewhere).

Okay? Replace the light bulb.