Go to the site https://www.kvaser.com/ The company is engaged in the production of equipment for working with CAN. In the Support section, you will find a link to the knowledge base, which describes the steps from beginner to advanced. The website also publishes announcements of new features for working with CAN and news of the IT industry in the context of vehicle electronics.
This portal is suitable for self-education as the company offers a free course about CAN and provides a good theoretical basis for working with vehicle electronics. https://www.kvaser.com/support/knowledge-base/
This is a book that is worth reading for a those who want to learn how to work with the CAN bus. The author refers to videos and studies of various institutions on working with the CAN bus. One of the institutes has completely parsed the Mazda CAN data. The book is available only in English language only.
On the Comma cabana resource, you will find a demo project where you can practice analyzing CAN data and see how various parameters behave while the car is driven. This will help you better navigate when working with the CAN bus in your car.