I started playing cornet in the fourth grade in a little country school. No brass teacher, woodwind man for a band director. I got better than anyone else in the school by ninth grade (K-12). Then I moved to Orlando. Went to a large high school with a dynamite band Suddenly discovered that the large fish in the small pond idea had merit. I found a private teacher. He listened to me play for about 10 minutes and said that IF he were to take me on, I had to forget I ever played trumpet. I was a junior in high school. It was a shock. I listened to him play for about 2 minutes and said I was in. Best decision I ever made. With his techniques I was able to lay off for 40 years and comeback to high Ds and Es in six weeks of practice. At three months I have a solid hour of playing Baroque trumpet on a "C". I still blow longtones, pedaltones and lip slurs. I still play at least the first four Clark exercises daily in their entirety and am gradually getting back to where I was at 25. The short of this, get some private lessons. Don't pick the guy who spends time complementing you. Find the one who says you suck and he can fix it. Listen to him play and see if he can do as he says. Then practice...LOTS. Also learn to face the fact that you don't know nearly as much as you think and there is always someone who can teach you new and better techniques.