Where do you plan on placing your built ins? That will give us a better idea on desk placement.

This is what I envisioned.. but I am not sold on the desk and built in locations. I could also see the desk jutting out off the wall as a peninsula desk with the built ins behind it.

OR the desk in the niche where the built ins are and the built ins moved to the desk wall.....

You don't want your back to the door (Italian Best Practice) so the desk could go perpendicular to the windows facing the French doors. Find a small credenza or cabinet with doors to fit in that niche behind you for a printer or supplies. Hang a picture above and a lamp. The computer cords will run along the wall under the windows and you can get cord management to hide the wires. If there is room in front of the desk you can add a small guest chair. Move the guitar to the other side.

you can make an office room look nice or you can make it work. What do you need?

You didn't list what you actually need in the room, and what kind of office space you plan. Is this a professional home office? Do you do videos/skipe? Do the windows open to the front of the home? will others share the space? Do you play/write music?

What equipment must be included? How much countertop space do you require... so many variables. Do the items in the photo need to be included, open to purchasing anything new? Will you be painting? have a rug? window treatments?

I need both- look nice and make it work.

As far as function- it is a professional home office where I spend much of the week on a computer and on zoom calls.

Just need space for my laptop and double screens, and a printer. No other equipment needed.

Yes to painting- unsure color. Will add a rug based on desk placement. And window treatments— nice roller shades.