Drawing after nature is a good exercise. Drawing nudes is part of the classical education when learning art. To draw a person needs a bit of knowledge about the proportions and mechanical workings of our body. So drawing nudes is the start of it. After mastering this you can much better draw or paint people. Also it sharpens your perception for proportions, outlines and perspective. And since we all know our own body and have a natural perception for body language we more easily can tell if the image we draw seems about right. So yes, learning to draw nudes is a good recommendation.