Some fabrics do wrinkle more than others, and yours may wrinkle less after its first washing. (Sometimes fabrics with lots of sizing show wrinkles, but the sizing will be washed out.) I wouldn't worry about the wrinkles or try to get them out, because it's bound to wrinkle again while you're hand quilting it, unless you're doing it on a frame. Don't wash the unquilted top, because you will wind up with a mess.