This tells me you are not ready to be concerned with range. Follow the practice routine suggested by your teacher and don't worry about the high notes. Meanwhile, you can start doing some ear training, which can be found on the web at sites like musictheory.net. You don't need to have the trumpet for this. And if you can get access to a piano and some basic piano lessons, that will truly expand your opportunity for learning, hearing and understanding what those now-mysterious pitches are.