I agree with Liz 100%. He is just a little baby and is very, very scared. Put his cage up high like Liz said and cover an entire half of it with material (so there is a little hidey-hole for him), make sure he is kept extra warm (babies need warmth for growth as well as comfort - I suggest putting a heating pad on the bottom of the cage in a low setting if he is going to stand on it). Make sure he has warm, soft food served fresh twice a day as well as soft seeds (like millet, for example but, if you can, cook some whole grains for him and mix them with a jar of baby food -like sweet potato puree, very nutritious!) and put it on a paper plate at the bottom of the cage (cockatiels are partial ground foragers). Spend time talking to him but don't put your face next to his cage and stare at him (that's what a predator does!). If you are loving and patient, he will come around in no time at all.