Best ways to learn a language (from your home)

I know of rosetta stone and duolingo. are there better ways? I'm thinking of picking up a new skill as a casual activity. partially professionally, but also because I think it's both cool and practical to be able to function in other parts of the world (e.g., being able to travel in places where English is less prevalent)

Local library.

Look for college textbooks or ask the librarian there.

Duolingo is garbage, especially since they are now using AI.