Awkward space. But with some tweaking... Okay. Get rid of the entertainment center. Mount a flat screen TV over the fireplace, which I usually don't care for, but you can conceal it. Or put TV in another room. Put sofa on wall opposite fireplace. Move the patterned chair towards the center of the room, to the left of the sofa in its new spot as you are sitting in it, so you can comfortably watch the TV over the fireplace. Get rid of white chair. Too harsh a contrast with sofa and patterned chair and rug, not enough space. Maybe get a small bamboo chair or two, something light in visual weight and easy to move, for extra seating. I like the rug; I want one just like that for my family room but the contemporary style and colors are not working at all in your space, especially with the patterned chair. The only piece it works with is the brown leather sofa. You need something much more traditional in style. Do you want more colors, or are you happy with the brown tones?

Need pictures.

You don't need studs to mount a TV. These go into hollow wall construction. DO NOT USE THEM IN A STUD. They will hold really heavy items, and your TV is not really that heavy. I would have placed your sofa on the wall that you face when you walk in the door if there is room. TV should be mounted lower.

I agree to turn the sectional , why a sectional I have no idea but it is there now so make the wall on the right the TV wall with my advice would be look at Besta from Ikea to do the TV some storage and a small amount of display . Remove the display cabinet you have there , Take the blinds off the windows and get some nice drapes for the slider in a color from the new rug and roman shades for the 2 small windows in the same fabric as the drapes . I would start the art with a really large piece on the wall between the windows , get rid if the fake plant . add lighting , you will need to figure that out after rearranging the sectional since plugs for lamps will be an issue , A much more colorful rug will be IMO the place to start , find one you love .This space is large and bigger is not always better . My LR is a tiny bit smaller we have 2 seating areas but no TV Is this the only place for the tV? I see some little pops of orange so maybe a rug like this with nice blue linen windowcoverings