I have nearly exactly the same layout, except add a door in the upper left corner and replace your bottom wall with wall, wide opening, closet. My room is also longer than yours - it's 18'x18'. I have added Billy bookcases with the half doors and height extensions to either side of the fireplace. It looks good and the extra storage is a godsend. I would definitely integrate a desk into any built-ins you do, like the picture kellyeng posted. Obviously custom built-ins/bookshelves are nicest, but the Billys are fine if you are on a budget. You could buy the short ones and/or cut the Billys down to fit on top of the desk. I have found two layouts that work for my room. Obviously we have different furniture but perhaps reading this will help you. 1) float sofa in front of fireplace, put sofa table with lamp(s) behind sofa, put two upholstered/leather large chairs in front of left window, float loveseat in front of slider on right, put coffee table in front of sofa, place dresser for extra storage on bottom right wall. 2) Float sofa and loveseat in the middle of the room perpendicular to fireplace with coffee table between them. Put the two large chairs south of the sofa & loveseat, angled toward fireplace. Put dresser for extra storage on bottom right wall. My TV is above the fireplace since DH wants it there, but you can easily put yours in the upper corner since you have less furniture. I would recommend that, actually, since the closer you are to the TV the less comfortable it is to look up that high. You really just have to move things around until you are happy - at least for now. The room is awkward, no doubt about it. So, when I get sick of one layout I switch back to the other. I switched back to my Option 2 yesterday. DH laughs at me but hey, moving furniture is cheaper than moving.

This suggestion is kind of taste-specific and might not be your style at all, but I'll share my thoughts... What about this long, lounge-y leather sofa from Article that Chris and Julia put in their cabin? This kind of sectional that's more like a sofa+chaise won't take up too much room in the narrow space between stairs and kitchen. https://www.chrislovesjulia.com/2018/01/sectional-frame-article-sofa.html With the floating stairs behind, I think you need something with simple lines, heft and no legs. The room could probably get cluttered looking very easily with those stairs, so my inclination is very minimalist furnishings. If you must have a TV in this space, I'd put it on the wall opposite the fireplace so at least you can view it from the kitchen. You could put a swivel chair to the left of the sofa so one could spin and see the fireplace. Personally, I don't think I'd worry about making the fireplace a "focal point." The sofa with the pretty stairs behind is a more important focal point, IMO, because it's what you see most prominently from the foyer, the kitchen and the dining room. Here's another layout that might provide some inspiration. Hefty, cool sofa flanked by a swivel chair and a bench. With an arc lamp. . . And a floor plan explanation:

I would flip flop the living and dining areas. In the dining area, I would do banquet seating which will help to get you a little more room. The tv would have to go in front of the big window which normally I wouldn’t suggest but I think it’s the best solution for your space.

Thanks for your feedback! As of now I don’t have any specific furniture purchased but have been looking. My main goal is to utilize both “living” spaces in the most functional, aesthetic way possible. I don’t want a bunch of wasted floor space and I want it to be cohesive/flow well so it just doesn’t seem like a random desk placed in a large room. I also was curious as to whether the way the sofa/chairs are arranged works for this room or if something like a sectional would be appropriate. Or if rearranging where the sofa/chairs would work better in relation to the fireplace/TV. Would love to update the fireplace (planning on a new mantle for sure) and decor in general, and make it more like some of these living rooms from my idea books. My goal is to achieve a coastal-modern feel, with richer woods and navy versus pastels and driftwood. Thanks for the tip on providing measurements - I’m new to this kind of software so I was sort of trudging my way through it :) I will try to get more accurate measurements ASAP.