I lived in a 7 by 9 foot room in a tiny apt in NYC for 17 years.
First, use your wall space. If you have tall ceilings - build a loft. I built a loft bed in the bedroom and used the space below as a desk.
I lived with a roommate and as many as 5 cats. Everything was stacked on shelves - TV and that kind of stuff.
The good news for you is electronic stuff is getting smaller.
If you can get free standing book cases, that has the advantage of being easy to set up. We built shelves, so you have to know where the beams in the wall are and how to put the brackets in so the shelves don't fall down.
We found a loveseat length couch that unfolded into a bed.
We had stacking shelves in the kitchen, bathroom and bedroom and covered cat litter box.
Also - careful placement of mirror tiles will make the space seem larger. If you have windows, consider viny plants like pothos instead of heavy fabric drapes.
It actually becomes a fun challenge once you get into it.
I just sold a 3 BR house and am living in a 1BR apt. I have floor space because I know what to leave in boxes and how to maximize closet and wall space.
Label every box you have and be mindful of weight, so you can move things as the seasons change.