There are many versions of the introductory video without a teacher. For example, Yu Manlong, Xie Jinqi and so on all have basic courses.
After that, you can look at the graded courses and recommend audio-visual products of daily art .. among which Xie Jinqi is the most classic.
If you want to go deeper, you can take a look at the jazz saxophone course. At present, Lu Tingquan's saxophone textbook is published in China. The rest is nonsense, all in the guise of jazz.
The saxophone is a fascinating musical instrument. As a colleague, I wish you good luck ~ ~ ~