How often do you have guests? Budget for now is for new bedding or something else? A Murphy bed would give a lot more space for the office use.

More lighting [how many lights are there now?]

Show more walls, each wall actually.... and what furniture is in both areas you want to form? how large is the room?

Headboard and art and lamps

The first thing I would do is to organize and contain all of the computer stuff. There are lots of desks and desk systems out there. Then I would worry about decor.

It looks like there's a printer stacked on top of a stereo speaker, stacked on top of something else. Right beside my head while I'm sleeping in the guest bed. It would make me feel as if it is about to topple on top of my head!

It would be better if some of these desk items were on a wall shelf, away from the bed. Can the computer go under the desk, or upright at the back of it? The black desk is very "office" looking. Or if the desk can be near the closet, could some things go right the closet with longer cords out to the desk? Or maybe the desk could even go in the closet? https://www.google.com/search?q=desk+in+closet+ideas&client=firefox-b&tbm=isch&tbo=u&source=univ&sa=X&ved=2ahUKEwjvvLSbxLjcAhVK2oMKHXHHBXIQsAR6BAgGEAE&biw=1194&bih=602#imgrc=_

If a new desk is not in the budget, painting the black parts another color would increase the "hygge" factor.

You'll get better advice if we know what you plan to keep and what you plan to replace. And also 4 photos (of each wall) as well as a floor plan with dimensions.

What is the brick-look paper on the wall? Your new wallpaper?