Huh?

I am really really confused right now about the whole season 3's main point. I thought it was to explain what before How to train dragons 2. But I am at the end of the season and I have no idea how it is linked to the movie. The Tv series is going to an entirely different direction.
So season 3 is about Dragon hunters, and it is still no where finished, more like lift hanger. Will there be more or it is it?
Hiccup and Astrid are not together at all, more like best friends. Heather is just a top weird on and off. I just don't get the point of this season and how it links to the movie at all. Haizz please tell me there is more and I am missing something.