NO LIGHTS FRONT OF CAR

You basically have parts of three systems

The headlights ONLY power comes direct from the ammeter black wire "welded splice" to the light switch B1 terminal. It does NOT power anything else.

The park/ tail/ dash are fed with a fuse in the panel to B2 on the switch.

I would start out front and find the grounding point for the headlights, screwed to the rad support, usually. If not that, suspect the bulkhead connector

Unfortunately there is no free download for a service manual. If you do not have one you should scare one up. Digital, paper repop, whatever

Also, in the case of a power surge, bad regulator, whatever, that causes too high charging voltage, it is possible that multiple lamps can be blown