If you want a nice rich look, be sure the curtains are all cotton, linen or silk or a blend using those three. Even Ikea has nice cotton drapes. NO polyester - it is basically plastic and looks cheap. I would go with a lighter color. The number of panels is based on whether you want more privacy or not.

I would skip the wallpaper as it is difficult to remove when you change your mind, and also the glue has toxic fumes. Paint a nice color or a nice beige.

Its a ruggable

This is the soca

color drench yes, as in no contrasting trim.

Not enough natural light to go dark, especially no the a dark ceiling. The floor looks great and a nice warm tone, so paint the whole interior a warm white.

If the space were flooded with natural light I would be all in on a dark green tone, even a taupe, but you don't have enough natural light to make it look right.

You need to prime first, so wait until you get the space primed out with a high adhesive primer so you don't have any bleed through and see what it looks like.

If you are interested in a green tone. Sample SE Reserved White it has a nice green undertone that will warm up with the natural wood tone flooring and the foliage from outside.

Remember the furnishings will darken the space, lighting is everything, make it cozy with the right lighting.