won't start, no power to anything

This sounds like a very dead battery to me. Of course it will run after it is started, the current is provided by the alternator. If the battery has caps on it, remove them and check the cells to see if they are properly filled with distilled water. Then run your trickle charger on it for a few hours. If it is a sealed battery, replace it.

"One summer at Jackson Hole I noticed various helpful locals try to get a truck started owned by two just graduated college ladies. They ran a charger over to it, jumped it with jumpers, and measured it with a voltmeter. The battery was at full voltage. The headlights worked OK. When everybody finished shoulder shrugging, packed up and left, I asked the ladies what the story was. It was a new battery that somebody sold them about a week earlier and it worked fine usually, but not always. I grabbed the battery cable connectors and tried to twist them. I easily pulled one cable off. The ladies had some tools including a proper wrench. Truck started right up.

Connections are the electrical problem about 70% of the time."

You have a relay issue, that’s why you’ve heard the fast clicking noise.

"Pretty sure if you check your fuse box there are some fuses one black a couple yellows the black fuses for a temporary parking so that there's no drain on your battery underneath that black cover is the fuse that controls your dash lights in the clock check that one and that should probably clear it up

Update (03/13/2019)

The fuses are designed to pull partially out so that the fuse does not get lost not sure what the yellow one do but the black plastic cover one controlled the dash lights the radio and cigarette lighter on 2000 Dodge Dakota"