They need more space, more attention, more money and have scarier bites. They're also typically much louder.
Make sure you're absolutely ready to deal with all of the above before going further. It's a bad idea to buy a bird unless you are sure. Many birds become cage-bound or given up to another home and go through environmental change because people realize it's tough work having a larger parrot. Of course given the nature of parrots, this owner and environmental change potentially wreaks havoc on their state of mind, making it a tougher case with each new person the bird gets homed with.
So don't buy a parrot unless you know you can give it what it needs. There's nothing wrong with deciding you can't or don't wish to deal with what big bird ownership entails. Deciding against a parrot because you aren't sure you can handle it is much more responsible, respectable and humane to the bird than "giving it a try."
Even a hand-fed bird isn't necessarily easy street, because when they mature they may go through a period where they get unruly and bite. This can be a crucial time; the bite(s) of a parrot during this time can scare a person off or cause them to "give the parrot space" enough so that all the benefits of having had a hand-raised bird go down the drain as it loses its socialization to people.
The point in all that is the first step to caring for a larger parrot is doing your (reasonably) best to make sure you intend to make your home its permanent home, and keeping it from a rehoming situation.
Otherwise, it's the same deal as budgies. Spacious cage with toys, plenty of time out of the cage, fresh fruits and vegetables, a lot of time with you (and others if possible), and of course money set aside should a trip to the vet be needed. Most important if you do decide to get a larger parrot, post lots of pictures in this forum.
Parrots give what you give. You put the effort into your friendship with your bird, and you'll have a friend for a very long time.
edit: After posting that it occurs to me that I don't even have a large parrot. LOL.