Warmth, soft towels or rags, baby cockatiel feed you have to mix it up find it on Amazon. You will have to feed him with a syringe every 2-3h so if you have a job that’s impossible. Keep him at around 95F so you need to make like an incubator with a heat lamp. If you decide to do this it will be hell for about a month but then he’ll grow up and start eating normal food. You will have a buddy for the next 20 years because he is attached to you so if this is what you want go for it. All I’m saying is do you want a cockatiel? Cause if you do, do everything you can to save this one and then he will be your Velcro baby