What an unusual shape! Perhaps you could google/pinterest some inspiration.
Using this image I found on google I would suggest decorating it as symmetrical as possible, as symmetry complements the room and doesn’t make it too busy with all the corners. You could put the bed on the wall side in front of the door, two bedside tables each side. And on the top half of the room you could put your dresser/wardrobe and on the bottom side a desk with a nice chair. But this all depends where you have your windows offcourse. So my essential tip would be keeping it symmetrical and in balance.
I know I’m not MrKate but I hope I was of some sort of help.