2004 Mercury Sable GS

Okay, I just changed my oil, oil filter, and air filter today. After I was done and started my car to move it out the way. It wouldn’t start. Instead it makes this clicking sound when my key is in the on position (not running) and then when I try to start it, there is an even louder clicking sound coming from the engine. Also, none of the dash lights are working correctly. It is acting like a dead battery. I currently have a battery charger on it.
I nee help please.

This morning when leaving to work there wasn’t any problems starting or cranking up.