Edward’s first lines happen several scenes after he initially appears.
First appearance: “Twilight”
Although Edward is in multiple scenes earlier in the movie, he doesn’t speak until Bella sees him asking to switch classes in the school office.
Before this, he didn’t talk during biology class even though he was assigned as Bella’s lab partner, as he was holding his breath to stop himself from inhaling her scent.
Edward’s first line in the entire series is, “There must be something open. Physics, bio, chem …”
He speaks to Bella later — after he’s hunted and missed school for a few days — and says, “Hello. I’m sorry I didn’t get a chance to introduce myself last week.”