1) It means "Have you ever cooked a 3-course menu". It asks if you have done this at one point in the past in general, not about a particular menu. "Schon einmal" makes this clear. 2) It can be both translated as "Did you see the movie?" or "Have you seen the movie?". Perfekt and Imperfekt in German are used differently than present perfact and simple past in English. In principle, one could also ask "Sahen Sie den Film?", but because it's not about an ongoing action, but a single action that's already finished, one would always use the Perfekt.