It happens that sometimes, really clueless owners will try to feed the bird something inappropriate, like in the story I read in Bird Talk of an owner trying to feed a toucan a certain sugary cereal. Make sure you get food appropriate for your bird. Learn its body language. Find out how to tell if it's healthy, sick, lonely. Ask your avian vet all your questions.
Birds can get very sick very fast.
Beware inobvious poisons. It's poisonous to them. Watch out for poisonous houseplants, too. There are doubtless many other things to know.