If you need to start learning this foreign language or you want to improve your level of German, then the best solution would be to look for German courses taught by native speakers, for example, such as here
ru-geld.de/en/german/levels-and-tests.html#for-work . I like that on this site aren't only text or video lessons, but here you can find any study materials for any level of German proficiency and practice it at a convenient time for you almost free.