If the answer is no, then I can NOT recommend your first attempt at driving a motorbike to be along the Ha Giang Loop.
The reasoning is because the Ha Giang Loop is full of very steep terrain, sharp turns, large vehicles passing by, and at times rain and fog. If you are not comfortable driving a motorbike then you simply would not have fun, and the Ha Giang Loop is no place to start practicing. This is just my personal opinion, so proceed at your own risk.