Where is the TV? A light colored rug. Get rid of the dark draperies and lamps.

Can you get a picture of your room from the Long part? It looks like your fireplace

is across from Couch and the that the two chairs are off centered? I would get a larger

lighter colored rug. Also would get a smaller coffee table. The side table

looks crammed against the couch. Also would probably remove mirror for art work or something else. What style are you wanting? I think if I was keeping the sofa and chairs I might go more transitional. But it’s hard to tell what the rest of your house is. Can you take some more photos. I am sure you will get a lot of help.

See additional photos

It is open to the kitchen
See photo

IMO everything is tuscan/formal. I would first do a lighter paint color

This is not going to be easy as both the fabric & style of sofa & chairs do not lend themselves to a casual look. The sofa seat cushions look flattened & worn. I'd probably save my money & start with a new sofa as that's the elephant in the room. Since you want to keep the sofa & chairs, I'd remove just about everything else that looks Tuscan...all the metal do-dads, the art, the drapes, the heavy looking lamps, those red candle holders, the throw pillows & large mirror behind sofa. Get updated sconces, updated art, more modern pillow fabric, different rug. I could work with that coffee table for now as long as you don't add Tuscan decor to it. I can't be more specific since I don't know your style & "casual" is quite vague. What makes the room look out of date is the heap of Tuscan decor all in one room. I'd also repaint. That wall color now looks like a Tuscan gold but maybe you might save repainting for when you decide on a new sofa. Don't throw anything away yet...once you update the room, SOME BUT NOT ALL of that those Tuscan pieces might fit in an eclectic way.

Ok I would paint. Take down the drapes for something linen would move tv I do t like TVs over mantel but I would do this in your case. I would go ahead and

move the two chairs across

from a new coffee table that is more farm french country. Make the tv area into a bar or a pretty hutch or something. I would get a larger rug. Take down the mirror for some art work I also would take down the iron pieces. Does the lounge chair have to stay? I would go for more French farm house look. simple unique pieces. Also a larger rug.I would get lamps that are lighter and more unique the iron ones seem dark and more formal . I think you got good advice to remove stuff from the room and get a clean slate good luck to you

Sorry one more thing would change

out the fan for nice lighting piece

maybe chandelier. If you need fan up date that one for cleaner look no light piece

Everything said above except, with Beverly's rug, I think you can keep your drapes - just lose the valances.

I spent five minutes

looking for rug not perfect but lighter like this.

Because you mentioned you were willing to change anything other than seating, I have lots of suggestions. The biggest impact will be window treatments, paint and rug.

I would replace living room drapery with cream drapes only on sides (Ikea sells nice ones at a very good price) and would also remove kitchen valances and one idea is rattan for a casual look

Would paint the walls a creamy yellow (and kitchen as well, given the open concept) and change your cushions to light cream solids and some patterned ones that contained your couch’s color.

A larger rug is highly suggested and a simple style like below is modern and easy to decorate around if you change your furniture down the road.

Eventually think about replacing the heavy accessories with lighter pieces, black lamp shades to white and remove the iron work. See below how your fireplace could look lighter and reconsider replacing the mirror over couch to one that is more casual.

Not a ton of money to do, just planning and a bit of work. Good luck In achieving a room you love It’s a bit harder given the formality of your couch but if not casual enough, above will feel lighter and more modern.

I'm with Samondragon, strip down the room and go from there. Paint would go a long way in your space too.