I have come up with numerous exercises for you to play. I also have a method of learning improvisation called the 1-2-3-4 Method. Contact me here to get your hands on this easy way to get inside of improvisation, 1-2-3-4 notes at a time! But the most important thing is warming up. Long tones on your saxophone. Octave jumps. Overtones. Building a correct, focused saxophone embouchure. Nothing builds your stamina, focuses your embouchure, and gives you control like long tones. There are videos and exercises below to check out. If you have questions, shoot me an email or better yet, lets have a lesson! But for now, play your saxophone slowly, evenly, and at about mezzo piano (mp).
Here are pdf’s of exercises-