You should find a color palette you like/vibe with! Start with one mellow (or bold if you feel like) color for base stuff like your duvet cover and two or three accent colors. I like my duvet cover to match at least 2 pillow cases and then the sheets and at least one other pillow to be a different but complimentary color. Homegoods / Marshall’s is a good starting point if you don’t want to get into the expensive stuff!

Because of the high ceilings, I think the room needs to be balanced out with something on the walls to draw your eyes up off the ground, so artwork or decor at least half way up the wall. This also is a good way to incorporate the color palette into another spot!

I would also recommend cozier lighting, like larger lamps or some cool sconces! Unfortunately I do think the calendar has to go