we are going to eat dinner before we go to the film. 講我知中文係咩

we are going to eat dinner before we go to the film.
In english, we wouldn't say EAT LUNCH or EAT DINNER, instead, we should say take or have dinner. So the sentence should read:
We will have dinner before go to the film.
我們看電影之前會先去吃晩飯

我們在看電影之前會去吃晩飯