The fabric on your sofa is quite a bold statement piece so I wouldn’t add any additional large pattern. I would take the pale blue from the sofa and try to find two comfortable chairs in that plain colour. Then find a 10x12 area rug that has a very small pattern (like pin stripes, small dots, etc.) in a green that again is found in the sofa. I would stay away from red unless it’s a for small accent vase.
Q