I can highly recommend this "How do LLMs work (with code examples)" video.
www.youtube.com/watch?v=YmLp...
It is extremely well-done, it touches all relevant details in an acceptable depth for an ~1 hour video.
This also proves it is often worthwhile to produce a fresh textbook/explainer.
youtube.com
I Built an LLM From Scratch
YouTube video by Syntax