I so agree with your recommendation to read books and watch films. To me, that’s just crucial for learning another language, even if you are living where that language is spoken.
I lived in Montreal for a few years and interacted with French speaking people everyday. I was totally immersed. My kid and his friends even spoke French around the house all the time.
But I never really mastered French to the point of being comfortable in it until I read books with attention, kept notebooks, and watched films until I got them thoroughly.