When watching new content, you will initially understand very little.
First of all, try to get comfortable with not understanding!
Second, you don’t need to understand the words as long as you understand the message! If you’re watching a clip with lots of context, e.g. someone going to a movie theater counter and buying a ticket, you may understand perfectly well what was being said (‘Are there any tickets for this movie?’, ‘Could I sit at the front?’), without understanding any single word. This is great, as you learn the language directly and unconsciously (you go from target language words directly to images, instead of taking a detour to your native language).
Ok, but suppose we don’t understand the message?
That’s still fine. Now the next step is identifying what is causing your lack of understanding: what is the gap in your comprehension?
We’re doing this at a sentence-level*. Does the sentence have a gap in:
If you’re not able to identify the gap, it’s likely that there is more than 1 gap in a single sentence. In that case skip the sentence and just be ok with not understanding. If there are a lot of sentences with more than 1 comprehension gap, try to find easier content.