Generally speaking, when you go to role-playing game, you should have at least some blank paper and a pencil.
In your case, as this is a beginner event, they will very likely be providing the books and dice, and pre-printed character sheets, if any. However, do not expect them to provide a writing instrument for you, and this is quite vital.
In any game other than Star Wars (Fantasy Flight Games), you might be expected or encouraged to bring your own basic set of polyhedral dice. Anecdotally, demonstrations at one of my Friendly Local Game Stores would not provide dice, and would advise new players to go to the main room and purchase a Chessex set.
However, this being a Star Wars event, you can expect them to provide the dice, as the game uses special dice that no one has. (Also, at time of writing, the dice are expensive, backordered from the manufacturer, and generally hard to come by, so if they expect to teach players the game, they would have to provide them.)
You should not be expected to have the book for an introduction or demo. Keep in mind, the store is running this event partly to encourage you to buy the product, so already having the product would be counter productive.
If the demonstrator/instructor is kind, they may provide blank paper for notes and writing instruments, but do not count on it. You should always have something to write with and write on.
If you want snacks or drinks, you should bring your own (unless the game store sells some, in which case, purchase your snacks from your game store). Do not expect the demonstrator to provide them, or the other players to share. That said, bring extra and share if you can manage it.