Not a pro but I can start by saying you have way too much furniture in this room and need a smaller (perhaps glass) coffee table. Can you put the chairs or love seat in another room?

Your furniture and floors are dark so I would suggest a lighter rug and then pull colors from that for matching pillows/throw. Also I would add lamps to your end tables.

Unclear about the ac unit so no suggestions for curtains.

Hopefully others will chime in with more help.