We are energized! I finished all the wiring, did all the plugs and light boxes and fixtures, wired all the circuits into the pony panel, and powered it up. It all worked! This was a major feat for me, considering how I objected to the prospect of having to do the wiring myself.
There were two 3way lights, and they worked(!) and all the plugs worked, and there were no awful popping sounds or smoke. Just one light fixture in a series wouldn’t turn off with its mate at the switch, but when I studied the diagram more deeply I saw that it was drawn for one light on a switch and one with continuous power (who would want that?), which is exactly what I got. I managed to fix it, anyways so both are switched
I’m very pleased with myself. I just worked through it all slowly and methodically with the code book in my hand, assiduously following the wiring diagrams. Electrical still makes my brain wobble, but I got ‘er done! Yay! It’s like a real barn now.