Carnival is pretty uniform in food quality from ship-to-ship. The menus are fleetwide. The Triumph has two main dining rooms and the Lido buffet. You will be assigned to one of the main dining rooms.
There is lots of good stuff in the Lido buffet. A deli window, an oriental food window, pizza and burgers out aft by the pool, as well as traditional buffet lines. I think sushi is also available at certain times.