You could add some paintings on the walls, carpets, some props like a blender in the kitchen, toaster, coffee machine , etc… , more plants is always better and some storage like a drawer.
Add a floor trim on the walls
Make it less spacious so you dont have an entire collage campus to fill
your couch is taller than you… and everything else, so shorten it
Your lights are just lanterns on the ceiling and your ceiling is just flat which makes the whole space look flat, add different heights in your ceiling with different lights
You have one carpet that I can see, and its in the kitchen, put it in the livingroom space and replace the kitchen floor with either a tile or a different wood style.
Make the floor a smidge darker as It’s dragging all the attention towards itself and not the furniture, making it look empty. The walls should be lighter than your floor so it makes people look up instead of down
coffee table is also very tall, fits with the couches height but it’s all for giants, being that large
add an island in the kitchen if you stil need to fill more space
hope this helps
As @Aerophagia said, the scale of the entire area seems too big.
Try selecting the entire room and resizing it to the scale of your avatar. If you select a group of items, or a model, the resize tool will resize them all at the same time.
I was also going to recommend the same things as Aerophagia but they beat me to it.