What IS your aesthetic? Traditional, transitional, contemporary, boho, rustic, MCM? Looks like you use the room for many activities. Will that change with the makeover? A good general rule to start with is that optimal, secure and restful sleep is attained when the bed is opposite the doorway. That would put it under the window, but it can be done attractively. Why not empty the room of anything that won't be staying, and bring in the bed and desk you plan to use? Take new photos and let's get started.

A small sketch of the floor plan is needed to design a furniture layout. First, overall dimensions of the room. Then go all the way around the perimeter indicating all measurements. Would be happy to help.

We need a floor plan to scale , what is the blue thing in the corner and also we need to see the new bed and desk also post the size of both of those Of course we need to know what your style is .It would be helful to know if you are male or female too.

It is rare that a room that size is a design problem! I see that you use this room for several purposes. Here's a floor plan without dimensions 15' x 20' and a layout that might work for you. Obviously, the only logical wall for the bed is the only solid wall, where you have it now. I feel you should create a sleep zone and work zone.

Consider placing the king size ? bed in the middle of the room, creating a sleeping zen area. Place some sort of scrim or a four poster bed with a high headboard to conceal the work area of the room. You have room for a lounge area across from the bed. When entering the room, you will be met with a zen and calm visual.

The desk and storage/dresser, cat tower ?, and keyboard can all take advantage of the long wall.

A simple 4 poster bed with a free standing divider between the sleep zone and work zone

^ ^ ^ Create a composition at the end of the room next to the double closets for work related items and/or a dressing area.

I love Denise Marchand’s idea to float the bed in the room to create zones. I also love your idea of a brown and white color scheme. Since your bed frame is dark, I would keep the bedding light. To create a backing for the bed and nightstands, you could hang beaded bamboo - just drop it down from the ceiling so that it reaches the floor.