You really do need someone who will play along with you. It's so important for you to get the proper concept of how a trumpet should sound. You could also be starting out on a "G" when you should be playing a "C". Playing along with an instructor will also help you with playing at a steady pace and show how long to hold out notes. When small children learn to speak it's from imitation, trumpet sound is much the same. It's easier to try to match you instructors sound than to learn on your own. Good luck, and don't feel like we're all against you. Many of the folks on this board teach students and know how important good instruction is, particularly when you're first learning.