https://youtu.be/kCc8FmEb1nY?si=zmBleKwlpV06O3Mw
I thought this video from Steven Wolfram was also quite good:
https://www.youtube.com/live/flXrLGPY3SU?si=SrP1EJFMPJqVCFPL
https://spreadsheets-are-all-you-need.ai/
The goal is to quickly get the viewer up-to-speed on what all the components in the Transformer are conceptually doing. Having something interactive like a spreadsheet also makes "playing" with the guts of a transformer more accessible. That being said, it focuses on inference and is unlikely to ever cover the training process.
Having been where you are before, I'll say the most rightfully and universally acclaimed videos are Andrej Karpathy's zero to hero and Jeremy Howard's fast.ai courses. I have watched both. My characterization is Jeremy Howard's is very practical and gets you productive quickly ("top down" so to speak) while Karpathy's builds everything in detail from the bottom up. My mind is more compatible with the bottom up flow of Karpathy's videos but Howard's might be better if you want use this immediately in a project or job context.