It's the only thing stopping me from the Kupper. so far im easily able to use all other weapons but any ghost that requires 2 candles isn't working for me, i don't get it...

The ghost has 3 state. Wandering, hunt idle, and hunting.
Hunt idle is when the ghost start to hunt, it will appear and we can see it, but they would not move immediately.
The location where the ghost appear is it's spawn point. Place 2 lit candles there before it goes hunting, and it should work.