Help with rug size, other ideas!

Im getting a new office at the end of next week. The office requires a rug for soundproofing/echo reduction. The office itself is 12x12 exactly. My desk (pictured) has to be at the bottom left area of the photo for data port access. I plan for it to face the door/back to the wall. I have (3) 27in monitors mounted via arms.

I’m horrible with design and would love any/all ideas!