The movie is just different it has a whole different story but some of it connects to the show???
Think of it like a famous video game, the game gets enough popularity (example) and it gets turned into a show that game plot gets into the show and some episodes include that making it an arc and the rest of the shows stuff is unrelated to the game
T H A T W O U L D N E V E R E N D
one of the reasons that TPOT exists (bfdis 5th season) was because THERE WERE LITERALLY 64 CONTESTANTS THAT WERE IN THE PREVIOUS SEASON (BFB) AND THE SHOW WOULD END WHEN THE CREATORS WERE AROUND 40