Came out to a dead car out of the blue. Got in with my key. (by turning it the old fashioned way) Nothing electric works but it's a stick and I was able to push start it. Runs fine but nothing on the dash lights, nothing electric works, of course the ignition doesn't work. The battery is fine though it doesn't seem to be doing anything. Checked fuses and connections. Any ideas? Thank you.

Assuming the battery isn't discharged- You do measure 12.6VDC without
the engine running, eh?
Start by cleaning the battery terminals with a battery wire brush and re-tighten.
If that doesn't fix it, service the (-) ground connection to the frame.

Bill

Thank you aws-ses, I went ahead and serviced the terminals and the chassis
ground for good measure and low and behold, it started and everything
works. I'm so glad it was something simple. Those connections all had
looked clean but going through the motions anyway, paid off. Please keep up
the good advice!

Check the connection to the starter sometimes the small wire that clips on gets corrosion on it and causes this.
best
Vinnie