There are very few resources for learning C which aren't themselves full of terrible C.

If you want a short introduction with the caveat that it only covers C89, only covers parts of it, and doesn't cover e.g. POSIX or anything outside of standard C then K&R2 + errata is fine.

If you want a long book on C which has a more modern approach then there is K. N. King's C a Modern Approach.

Jens' book is at least vouched for by https://iso-9899.info/wiki/Books . So I have to assume it's also okay.