Thank you so much ! I really struggel with that room!

Enjoythejourney gave you good advice.

You might also consider a sofa floated, with 2 chairs along the window. This would give you a furniture grouping and nice conversation area. For new furniture, conside smaller scale.

The rug is too small for the dining room. You don't need one and I'd just remove it. The buffet is also crowding the dining room. If you are not displaying dishes in it, you could consider placing it where the fireplace is below. Then place the art in the dining room.

Center the dining table under the chandelier.

I'd hang the drapes 2/3 of the way between the lower window and upper window. They should be light in color and the panels should be wider, extending beyond the windows.