How to make this living room more personal and cozy?

I recently moved in into a new apartment and this is my living room. Looks kind of stale with no personality and colors. The entire apartment is white and gray, what can I do to the living room?

I wanted to add plants in the two corners of the couch (right and left side of the pic) and possibly a lamp or a small desk. Maybe change carpet color and put couch sheets in some other color, I just don’t know which color and where to start. I am on a budget.

Any suggestions? What would you guys do here?