The age of the bird has no correlation to what they like or don't like.
My Phoenix chicks at a month old are eating fermented scratch, leafy veggies, grass leaves, superworms meant for adult birds, beetles, spiders, centipedes, and flies.
I don't give my birds any of those vegetables you listed they don't like them. I give them kale, spinach, romaine lettuce diced up and shredded carrots.
With hard vegetables they need to be cooked and shredded or mushed up.