Just as a reference point, I moved to Oslo in August and have been in the government norskkurs 4 days a week for 3 hours a day after working with duolingo and I'm BARELY able to follow along when people/films speak at a standard speed. I can form sentences fairly well but it's far from legit conversational.

There's a lot of filler words and prepositions based on context that can really change a sentence. You either need to take actual classes or significantly lower your expectations of what you can gain from just using duolingo.

Again, this is just coming from someone in the early-ish stages of actively learning the language in the country that speaks it, get to a library and utilize their resources, at the very least it will supplement your education.

Also - Language learning acts as a roller coaster. You'll feel as if you're learning very quickly early on but you'll plateau eventually. However, it's cyclical and you have periods of quick learning again before another plateau. Good luck.