I'm having trouble with the nodes in the fog object

no I connected the principled volume to the volume in material output

If you are using Rendered View, with Scene Lights enabled, but with no lights in your Scene...

You don't give us a lot of information, so we are just guessing...

here's a screen shot of my view port display. Don't mind the extra window on the right. Sometimes the view port will be dark and sometimes it will be clear

scene light and scene world were both checked

The 3D Viewport doesn't give me any information; you already told us that it was black ;)

And the Shader Editor doesn't show the Fog...

But if it is sometimes black and sometimes clear, then my guess would be that it is your Graphics driver (that is not up to date).