Help me fix my fugly living room

I have lived here for five years, and it’s time for a change. Most of the furniture is cheap and things I bought when I was super broke, or shared with various roommates. But now that I have a bit more stability and will prob be staying for a while, I want to give everything a face lift.

It’s a rental so unfortunately there is nothing to be done about the tile floors. The space itself is large, but doesn’t get much light. The sliding door (which leads to an extremely small patio) is east facing.

Please help me figure out what to do with painting. The style I’d like to embrace is rustic / MCM, but the tiles and overall dark walls makes it feel like a cavernous and cold space.

My goal is to lighten and brighten the space.

I’d also like to replace the couches with one big sectional and maybe an arm chair.

Any advice is appreciated!