I would start out with a large, beautiful rug in warm colors (terracotta or red Oriental rug mixed with other colors. I feel sectionals often confine you in how to organize your room. I would choose a fabric couch in a neutral, not too dark color (not gray, which is on its way out and not a warm color), and add two chairs in a different color or at least a different material and style. Try to keep the height of these pieces similar. Two end tables in wood (they don't have to be the same, but make sure the heights are fairly similar and a metal and glass coffee table would look great, with table lamps or floor lamps even if you have overhead lighting, which is always harsh. Pick colors from the rug for pillows and you'll have a beautifully coordinated living space. Books, good paintings and some tall plants will add warmth and personality to your room. People too often don't add these elements and then wonder why their rooms look bare and cold. This may be more colorful than you want to go. and this is a small rug because there is carpeting underneath, but it gives you the idea of neutral furniture and how it can be made more lively with accessories, pillows, coffee table styling etc.

The rug is the wrong orientation in relation to sectional. Rotate the sectional so the chaise is on the fireplace wall. Or pull the sectional back, center it on the fireplace, and rotate the rug to center on the fireplace. And remove the pieces from in front of the fireplace so the rug can be closer to it. Can you separate the sectional into two pieces facing each other, one under the window and one on the wall -- and rotate the rug down the middle between them. That woud be ideal...you could see more of the rug. And get bold artwork for the long wall that will compliment the bold rug. Go to greatbigcanvas.com ,for a large canvas print..a fun site and reasonable. 60x40 or 48x32. I searched for peach and teal under Abstract and found these: https://www.greatbigcanvas.com/category/abstract-art/?color=382&color=398&shape=1

I found some black out curtain online and they look full on my windows. I would recommend using black out curtains over un lined curtains, unless the curtains were sheers. Also I think panels should be 2 to 2 and 1/2 the width of your window. My window was 7 feet wide and I ordered four 51" panels. The curtains look great open or closed; they still maintain their soft grommet spacing and design. Unlined curtains. they give a softer look but the pattern if bold and busy so can disguise lack of lining........I think these are probably always open? These are lined and have a a very 'still' look. Can be closed or opened; note how close rings are.....very unique style. My two cents. Good luck.

Your sofa is neutral color, so any color would work.