You do not want to be unhappy with your choice of bird. Bird nutrition all depends on the type of bird you own. For instance, a pet bird that's a carnivore would have a different diet than a nectar sipper. Birds need a balanced diet. They need a variety of vegetables and fruits, as well as pellets and nuts and even seed.
Some birds are picky eaters.
If your bird is a picky eater it will sometimes eat foods that it sees you eat. Also, get your bird to try new foods by handing the food to them when they are someplace they are happy such as a certain perch in their cage or out of cage on a playground, etc. Never starve your bird into eating new foods. To get your bird to eat, give your bird his favorite foods, but also a variety of different foods. Birds are intelligent beings.