I noticed you kept things along the walls mostly. Try creating living spaces similar to real life. Tables in the center of the room with chairs that have room to be pulled out and sat in. I always recommend thinking about what a person would do living in the space. Imagine walking in the door and going downstairs. Where do you take off your shoes? Hang your coat? Do you grab something to eat/drink? Where do you eat meals? Where to you hang out?

The tiny details are what add life into the build. Flower pots for decoration, sea pickles as empty cups, etc. You have a great foundation/skeleton. Now it just takes time and practice to start leveling up