Some websites offering free German language resources:

To fully master the B1 level, you should ideally have access to:

The textbook "Menschen B1" is part of a series of German language courses published by the Hueber Verlag. It is designed for young adults and adults who want to learn German in a practical and communicative way. The book includes:

While official digital copies typically require a purchase, many platforms host free educational resources, including textbooks (Kursbuch), workbooks (Arbeitsbuch), and audio files.