Surprised your agent couldn't answer your questions, but the Captain's night is the 2nd night (Sunday night), which is formal. And the second formal night will be on the 6th night of the cruise (Thursday night).
While the food in the main dining room is okay (tough to feed 6000 people in 4 hours), all the specialty restaurants are very good!
__________________ 47 Cruises & Counting! Favorites: Paul Gauguin to Tahiti: Uniworld River Cruises in Europe; any of the Celebrity Solstice-class ships; Holland America for 12-nights in the Baltics & Russia; RCCL for 14-night Greek Isles, Turkey, & Croatia; Holland America for 14-day Alaska cruisetour; 10-night Canada/New England cruise; 21 days in Hawaii including a 7-night NCL cruise; Oceania for 25 days in Asia; & 3 months touring Europe by train. And many days spent in all-inclusive resorts!