I'm currently using John O'neal's Jazz Method for Trumpet book. I'm currently working on "Home Bass" and "Samba for Maya". These are obviously very early pieces in the book.
I've worked through the previous lessons before and I am able to blow all of the notes for required for these pieces. Just the same, I quickly fatigue in terms of embouchure and in terms of air too. This horn seems to be far more demanding that the sax.
Anyway, I just thought I'd toss this out there for any potential encouragement, support, or advice.
I've only just now got a handle on the A note. So my note "repertoire" at this point starting at middle C is, C, D, E, F and A. That's it so far.
Although I imagine I can hit the sharps and flats of those as well.
I feel good that I still have control over these notes because when I first started I couldn't even do this. So I feel like I now have at least 5 notes under some degree of control (and probably their sharps and flats). The next lesson in the Jazz method book teaches Bb and C. I'm managing to blow the Bb note already. But I'm still finding the higher C to be very difficult to reach and control yet.
I am quite patient though. So for now, I'm just working on practicing "Home Bass" and "Samba for Maya", right now. I do practice the exercises for learning Bb and C for the next section (chapter 4 in my book), but I'm currently I'm not there yet.