Easy questions first. The engine will likely run in all positions except PARK, but the IGN is the normal running position. The others work the lights.
I expect this car has a vacuum tank for a fuel pump. You must take a plug out on top and put 1/2 litre of gas in the tank to get it running.
Timing the magneto gets more complex and there are a couple of questions. Does it have an impulse coupling. As in, does it make a snap for each cylinder when you crank the engine. I expect it does, in which case you need to very slowly turn the engine and watch the timing mark. It should snap JUST AFTER the upper dead center mark. If no impulse coupling there's a different approach. What make of Magneto is it?
A picture of the complete engine compartment may help.