The room seems a little bland.

I would suggest picking one or two accent colors and then adding complementary pillows, wall art and a throw.

You may want to introduce a shiny mirrored object to bounce light around the room.

Pull the rug to within 12-18" from the hearth and float the sofa facing the FP on the farthest end of it. I only see one chair. Is there a mate to it? Flanking the FP would be a good move it you have a matched set of them. I rarely suggest TV above a FP, but if you're going to watch in here I think that may be a good spot for it if it fits. In that case you could put the two chairs in the window. What is the dark vertical piece left of your photo?

I love your room color....very pretty! I would remove the blinds on the windows or at least soften them with flanking panels or cover them with sheers.

Since your foyer is small and full of stairs, placing the sofa with its back to the entry will allow you to add a sofa table behind it to create an extended foyer effect. Try making that move now, aligning the sofa perpendicular to the last portion of your window closest to the entry. Then we'll see how much space is left for a coffee table and the two chairs, plus side tables, lamps, etc. If you don't have furniture sliders, use old towels or cut the bottoms off of plastic milk or juice jugs.

This is an option for you. Keep the sofa in front of window, move bookcase to left of FP, add tall potted plant on rt.

Pull chair onto rug and add another chair by sofa. Invest in a long console table for wall opposite sofa with lamp and art. End tables and lamps

This would keep your entryway open into the seating area and a pathway to the other opening by FP to the rest of the house.