I'm very confused. I see these path nodes I want to delete. I tried to select all of them but I couldn't not. So I figured I could just delete them one at a time, but I can't. I clicked one and then pressed delete. Nothing happened, I'm really confused.

We'll need a bit more information than that. Where are the pathnodes you're trying to delete (i.e. interior cell, exterior cell, mod added cell, vanilla cell, etc.)? What color are the pathnodes (orange, red or blue)? Has the mod with the offending pathnodes been set as the "Active" file? Why do you need to delete them? That sort of thing.

Interior cell to a mod added cell, red, yes, I need to place new ones.

The reason this happened is that I duplicated a cell to make a new one.

In that case, I'm at a loss. Selecting on and pressing 'Delete' should remove it. Are you able to move them around at all?

I've moved them around some. Maybe it's because I'm on a laptop?

Possible. Have you tried turning your numlock off and seeing if delete works then?