How to start classical CV theory?

Hey guys. I am sorry if my question seems a little stupid when you read it but please read until the end and don't roast me at the first place.

I have read some books on deep learning, have learnt a lot about cv using deep learning and architectures such yolo and RCNN and even generative ones etc.

But, that's not what I am aiming to learn. I have searched a lot to find out how to learn the thing …

architectures books computervision deep learning hey theory yolo