Start wit he battery connections at both ends of the cables, make sure they are tight and clean. Then check the main circuit breaker (a volt ohm meter is the best way, but a test light can be used) for power going in and out. Then just keep moving along the power stream until you find the culprit. Pay attention to the ignition (key) switch and the stop/run switch. Although with the lights out it is probably one of the others mentioned. Hope this helps.
John

 

No power anywhere is easy to trace down. Start at the battery and go forward from there. Check your ground too. It goes: Battery to starter solenoid to main breaker. I bet your problem is in there or the battery ground wire.

As for the hard starting, are you using the enricher? Is the enricher lever actually attached to the enricher plunger thingie on the carb? It is not hard to put the backing plate on and not have that lever attached to the plunger properly. Don't ask me how I know that.

 

Does it crank, does it crank slow just not start?

 

If you want a quick check after checking battery to solanoid bypass circuit breaker just to see if you got full circuit, if it cranks you found culprit and if it acts the same reconnect circuit breaker and continue tracing.
By the way circuit breakers are cheap and do get tired.