At the very least by then, I will know my way around the instrument and also have a vague idea of what really should be the correct system, although I have not but mastered it! I had been recommended a tutor book about playing jazz sax by John O Neill https://c-sharp-dorian-scale-on-s35689.bloguetechno.com/about-d-flat-dorian-scale-for-saxophone-62095404