What is wrong with my car?

sounds like your alternator took a powder and then ran down the battery with the lights on last night. When you hook up a car with a good alternator, it works fine, as soon as you disconnect it dies, that is the alternator. charge up the battery for several hours, and then see if it starts, you need to do this while its light out, your lights take too much juice from the battery. A large auto parts store usually has a machine they can roll out to your car, and test the alternator, the battery and the starter. get this done, and fix the problem.