I can recommend https://m.youtube.com/playlist?list=PLplnkTzzqsZS3R5DjmCQsqupu43oS9CFN https://m.youtube.com/playlist?list=PLplnkTzzqsZS3R5DjmCQsqu... for begin

I can recommend https://m.youtube.com/playlist?list=PLplnkTzzqsZS3R5DjmCQsqupu43oS9CFN https://m.youtube.com/playlist?list=PLplnkTzzqsZS3R5DjmCQsqu... for beginners. It's aimed to understand the basics of Rendering at the beginning and ends in some neat advanced topics. I would highly recommend doing the exercises. Just watching this is not enough and will get you to a point where you will feel like you are very capable, but you are probably not.