The main character is the man. He is the one who has a relationship with the wood, whether he is cutting it, using it for building, or some other activity related to the wood.
The main characters are likely the man and perhaps the wood itself could be considered in a way as it seems to be an important part of the story.
The main characters are usually the two children left in the woods.
Since I have no knowledge about this story, it might have a brave explorer as one of the main characters. Maybe there's also a wise old hermit living in the wood who helps or hinders the main character's journey.
Since I'm not entirely sure of the specific 'Belleau Wood Christmas Story', it could be the soldiers who were stationed in Belleau Wood. They would be the main characters as they are likely the ones experiencing the Christmas in that location.
The main characters are probably the little wood duck, and perhaps other animals in the wood where it lives. For example, if there are predators like foxes or hawks, they could be important characters too as they pose threats to the duck. Also, other wood ducks in its flock might be part of the story.
The wood carver would be the central figure. There could also be his customers, if he sells his carvings. Maybe there's an old man who gives him advice on wood carving techniques, or a young apprentice who helps him during the busy Christmas season.
Since I don't know the exact story, it's difficult to say. But surely the boy made of wood is one of the main characters. There might also be the creator of the boy, if he was made by someone.
The old woman herself is a main character, of course. She is likely to be the center of the story, perhaps with some sort of mystery or power.
I'm not sure specifically as I haven't read the exact 'in the dark wood novel'. But generally, there could be a protagonist who is likely a lost or confused individual trying to find their way in the woods.
I don't know for sure as I haven't read it. But typically in a story set in the woods, there could be a young adventurer as a main character, someone who is curious and brave.