I would paint out the very dark wall and remove the two small items on the wall. Also add a light toned rug with a pattern.

How about a light colored rug?

I think you need a colorful patterned area rug, large enough to fit under the front legs of the chair and couch. Your side table lamp needs to be at least twice the height. Lower the artwork about 4 or five inches. Put the two couch pillows on one side or add another in a pattern.

you're on the right path-you need to introduce textures other than wood, say metal finishes, ceramics (like stools that can function as side table), stone etc. Basically everything that reflects light some more. Wood can be incorporated too, of course. Soft textures as well for a rug..yes to lighter rug, just pay close attention to function..I see you have small kids, so you want something easy to maintain, and not a tripping harazd. I'd vary colors too-don't make things too matched..I for example would switch pillows on your cranberry red sofa so it won't look like everything is supermatched to art above.

Bigger credenza would be indeed very useful..both for proportion (visually) and function(storage)

If you like patterns-introduce them. Some have very modern sensibility. Geometry, some large florals...

Depends how streamlined you want your furniture to be, also whether you're okay with sharp edges etc, so I hesitate to post exact suggestions.

But as an example..

light painted metal coffee table

https://shophorne.com/products/tier-coffee-table

interesting side table..used material(transparent plastic) makes it modern even though the lines mock traditional tablecloth

https://shophorne.com/products/grand-illusion-side-table-clear

you can find all sorts of ceramic stools on Anthropologie website ..not only there of course..but again, just to take a look. These are heavy enough not to break them, but if you're wary about it-check side tables with similar sensibility but made of different materials.

https://www.anthropologie.com/furniture-end-tables

check also their sister site. Urban Outfitters (and read reviews closely everywhere-can be a hit or a miss)

if you like funny..)

)https://www.urbanoutfitters.com/shop/birdy-side-table?category=tables&color=070&type=DEFAULT

(sorry for posting links instead of pics..not every site lets you to save)

there are so many cool rugs out there

this is probably too matchy..but I still like it. Modern, simple, interesting. 100% wool-wool is easier to tale care of

https://shophorne.com/collections/rugs/products/chandra-counterfeit-series-cou-18213

Add texture/light fabrics in your pillows..(you can find these anywhere), collect art that speaks to you, without worrying too much about colors..sure, take into account but don't let room dictate you too much, art is art..group small things together-say photo frames..add live plants-these immediately bring life, color, and texture to any room.

Knowing your budget will be helpful..since I love to spend other people's money as much as everybody..and been holding myself from some cool suggestions..))

In your great room, light, neutral rug would make a huge impact in your space. It will provide great contrast between your flooring and furnishing allowing many design elements to really pop. With kids and pets, it can often feel risky to choose an ivory or beige area rug, but there are some great washable rugs as well as some outdoor rugs which are not as absorbing, low maintenance and can be hosed off outside:

Replacing your existing artwork with a smaller series of pieces would also help to alleviate some weight in your space:

Your dining room is on the right track! The contrast is well balanced and your space looks rich. A tall, shallow hutch or bookcase in place of the small buffet will help:

Best of luck with your project!

you have great pieces to work with. I love red couches. If it were my space..... I would move the couch to the wall the chair is on. Then angle the chair in the corner by the window. Get a rug to unify the space combining all the colors in the space and grounding it. Move the picture above the couch to the dining room. Center it on the wall with the sconces flanking it. you need to have your colors in both areas of the room. A few more pictures would help. I would like to see more of the entry and pictures showing how everything relates to each other. Easiest is to stand in each corner taking a picture of the opposite corner.

Well Woven Serenity Oscar Modern Abstract Lines Red Area Rug 7'10" x 9'10" · More Info

Safavieh Adirondack Adr116F Rug, Red/Black, 8'0" X 10'0" · More Info

I would start first with declatte room.