Post a photo here in the comments

I agree with Hallet that if you are able to post a photo, you will get much better and more specific advice for your room. But in general, covering the entire wall with curtains could be a missed opportunity to bring in some art or a mirror, depending on what furniture is in front of that wall and location of window.

Perhaps you are already aware of this, but if you hang your curtains as high as possible and use a curtain rod wide enough to stack the curtains to the sides of each window so they won’t block any light, it will make your windows appear larger and your ceiling taller: