The first is grammar rules.

The second is programming ideas.

For the former, almost, the grammatical rules of Fortran and C are relatively simple, which is just the content of a book.

The latter is more complicated and should focus on learning. In this respect, the two languages are interlinked.

Personally, I think that learning programming should not be limited to the understanding of grammar, but also deeply study the relationship between data, process and logic. It is the most important thing to throw out things that are outside the grammatical rules.