As part of the full immersion I recommend my students embrace when learning a new language, I encourage them to watch films and series shot in the original version and regularly send them links to the various viewing platforms (BBC iPlayer, Channel 4, Netflix, and Amazon Prime).
With an entirely new film/series, this is what you can do:
1. Watch it with English subtitles - for all levels, especially beginners to intermediate level.
2. Watch it with subtitles in the language you're learning - intermediate level.
3. Watch it without any subtitles - advanced level.
But first, make sure you choose the right film/series. Stay clear of those with very fast dialogues, slang, dialects, literary dialogues, and intricate plots. Read the synopsis first and, if in doubt, check with your teacher.
Secondly, make sure you adapt your viewing to your own needs and level:
A. If you're tired, too busy to study, or haven't reached the intermediate level yet, but still want to watch something, then option 1 is ideal. Even though subtitles are in English, you're still listening to people speaking the language you're learning.
B. If you're not ready yet to watch a new episode, or film, without English subtitles, I recommend re-watching one you know well with French subtitles, this time. Because you're no longer worrying about the plot, you can focus your attention more easily on the actual dialogue. This can be done with just one scene, your favourite scene, or the first five/ten minutes.
C. Watch an episode/movie without any subtitles, but only if you are ready for it. My advice is to wait and not reach that stage too early, otherwise, you will feel overwhelmed and discouraged, unnecessarily so. You will get there, but it takes time, practice, and patience.
I remember the first time I understood what was going on in a English-speaking movie without French subtitles. There's nothing like that milestone to make you want to say, read, watch, and do more in the language you're learning. So pace yourself and, if you're not sure, ask your teacher.
Don't hesitate to send me your questions.