car just lost all power?

It sounds like the battery shorted internally, I would try to turn the headlight on if they don't come on or are very dim replace the battery with a new unit. This guide will help you step by step with instructions in the diagrams below to show you how on your car:

https://www.2carpros.com/articles/how-to-replace-a-car-battery

Check out the images (below). Please let us know what happens.