It is best to choose a light-colored gauze curtain, which can not only shade the light, but also have a sense of transparency. Light-colored venetian blinds is also good, because the sunshine in the south room is stronger, and it will be much more comfortable to refract through the curtains, but don't pay attention to these in your north room.
In addition, learning should also have a backer to avoid being helpless, especially for students at school. Seats and bedside should avoid beams, and desks should avoid sharp corners of other buildings outside the window. Don't point the desk at or near the window to avoid distraction and drowsiness.
I don't know much about guzheng. Find it yourself. I hope what I said is helpful to you!