I'm not sure what you mean changing from sealed beams to halogen. I have halogen lamps that are sealed beam are yours a complete change out and just have the lens housing and plug the lamps into that?
I have two headlights on each side, a lowbeam lamp and a highbeam lamp, If I remember correctly they have the same contact configuration but different internal wiring so you don't have two highs or two lows on a side.
Testing the sockets by yourself is when a simple test light is great. Just hook it to the plug and lay it on the wipers and you can test from inside.