Manzanita perches are sold in pet supply stores if you don't have access to unsprayed trees. Plastic perches are also available but be careful that your pet doesn't chew the plastic as their bodies can not digest plastic which can cause medical problems later. You can also purchase wire platforms, and special flat perches sold for your birds foot health. Some people like to add a piece of 2x4 as well. There are a number of feeding dishes available in a wild variety of styles.
Some cages come with their own special dishes.
They rarely come with enough dishes. I have found that a water bottle is terrific if your bird likes to make pellet soup, poop soup, or just prefers a small bathtub. I did not find the style of gravity feeder I tried useful. Pellets are lighter and less slippery than the seed it was designed to handle so they didn't feed properly. That is the amount an average cockatiel eats per day.