@Chikaon
I'm unsure which movie you mean, but if you mean "Liz to Aoi Tori", I'd recommend you watch Season 2 since it introduces Mizore and Nozomi, including their overall relationship. Though I don't think the movie and TV anime series is considered canon (it's more of a side story if I'm not mistaken).
If you mean the third movie, "Hibike! Euphonium: Chikai no Finale", I would definitely recommend Season 2 since it's a direct sequel.