A little nervousness isn't a bad thing; it will keep you careful. I suggest using the nerves to sharpen your focus on your tasks. This will give greater assurance in your pre-flight preparation as well as during the flight. Eventually, the nerves will be gone, replaced with a vigilant state of awareness. This is a very good state of mind in which to fly any aircraft. It just takes time, but it can be developed fairly rapidly if you manage to fly regularly, and frequently.