1970 Chevy Camaro 1970 Camaro troubles

1970 Chevy Camaro V8 Automatic

ok, I have a 1970 camaro. About 2 weeks ago I went on vacation and prior to the trip, the car was running fine. During the vaction, I had a friend watch over the house and start the car up every other day for a few minutes because I didnt want it to sit. He tells me that after a few days, the car wouldnt start and he had to jump it. I said the its probably jus the battery. Well, I come back and there is absolutely no electrical power going to the car at all. The battery is fine and so in the alternator. Fuses are good. When I try to start it I here nothing at all. The radio doesnt turn on and neither do the lights. Ive been told that its the starter, ground cable, starter harness wires, ignition switch, etc. But honestly, I dont know.