The duolingo format was never popular with polyglots. The game format makes it easy to feel like you did something which is a great thing, but the is the only pro people who have learned multiple languages find with it.

There is a lot of debate about what the best way to start is, but all agree that you need to interact with the real language in real world type settings (watching a movie in the language with subtitles is real world, though you need to make an effort to listen not just read!) They also agree that time is important, you need to study at least an hour every day to make progress.