I was listening to music in the car and then as soon as I turned my lights on and wanted to start my car everythign just went off. Now I cant start the car, no lights or anyhting. Can't even open teh trunk with key. I tried to jump start but nothing.
Start by checking battery terminals to make sure they are tight, clean, and not corroded. If they are good, have the battery load tested. Most parts stores will do it for free. At this point (not running) the alt isn't doing anything, so we need to get the battery working again. Before you take it to be checked, make sure it is fully charged; otherwise, it will fail the test.