It means that your teacher thinks you are capable of safely riding an experienced horse in an unfenced area. Congrats! I remember my first trail ride, it was so exciting. :) However, don't set a number on the lessons you want to get before going up a level, for example, starting to jump. You will do better if you take your time and really, really polish your basic skills. That way, when you can start doing something more, you will be equipped with really good balance and confidence. Nothing is scarier than a beginner jumping without a really good balance and steering skills in all gaits! That's an accident waiting to happen. So good luck in learning and being patient. :) Good things take time to come.
I have come a long way, to surrender my shadow to the shadow of my horse.