Yes! Definitely smile a lot. And speak as clearly as you can. You’ll be nervous, but try. 🙂
And if you know what job you want, don’t be afraid to tell them. Disney job placement is kind of a crapshoot, and if you don’t know what you want, you’ll probably end up merchandise or quick service, and if that’s not what you want, you’ll be sad. So don’t be afraid to speak up! Tell them you want Magic Kingdom attractions, or Bibbidi-Bobbidi-Boutique, or whatever, and if you can, tell them why.
But yeah! Good luck, Disney anon! May pixie dust shower down upon you! 😀