First thing I'd do is check your kubeconfig file at ~/.kube/config and look for the server line to see if that's right.
I thought that error message usually gave you the server name & port you were trying to connect to, though I thought it was a different message talking about finding nothing on localhost:8080 when the file's just missing.
To test after you might want to start with just
kubectl get nodes
as a very basic "can it talk at all" sort of command.