Will not turn over or start

Old school, disconnect the battery and leave it unhooked for a while, charge battery with nothing hooked up to it. See if it will then hold a charge. If not check with a hydrometer to see if there is a dead cell. If does charge and while hooking it back up check the cables. Sometimes you cannot see it but a little corrosion will keep the battery from making a good connection. When the battery is disconnected it should use what energy that is still there will drain the computer. When you get it started you will have to drive it about fifty miles before the computer resets itself.