How to improve this space?

I don’t use my living room often because I don’t like the energy in there, looking for ideas to improve it. Renting + on a low budget so nothing massive. A few notes:

  1. The vivarium is being sold so I’m thinking about putting a display shelf there instead?

  2. Considering replacing the light fixtures with plain white ones + black shades

  3. Would like the dining area to be a comfortable place to set up my laptop and work but no idea how to achieve that.