Can one do these lessons in any order? For example, do CNN first then jump back to NLP. Or skip the implementation from scratch because I have done a similar one in another course.
They're designed to be done in order, but yup if you know how SGD works, for instance, you could certainly skip over that bit. The videos all have youtube timestamps, so if you drag the scrollbar you'll see what each section is about.
Or you could do those bits at 2x speed in case there's some concepts there you haven't seen before.
The NLP lesson could possibly work reasonably well standalone if you already know some DL basics, since it uses a different framework (Hugging Face) to the earlier lessons.
The CNN lesson would probably largely make sense if you already understand multi-layer perceptrons, since it mainly shows how a convolution is just a special case of sparse matrix multiplication.