Maybe somebody know good video/audio courses from where to learn?
There are dozens of videos on YT but most of them are worthless IMO, the most informative I know of (entry-level) is this:
https://www.youtube.com/watch?v=2aHkqB2-46kIt's the first of a series of lectures by dr. Christof Paar. If you can endure the camera instability and find it useful, check out his channel - he has 20+ lecture videos there.
thanks for this recommendation. this is informative for newbies in crypto.