Can a baby bird have water?

No, do not give it water by dropper. It is so easy for it to be aspirated into the lungs. If the baby bird is fully feathered and can walk/perch than you can place shallow containers around his little home.

you don't know how to care for THIS bird specifically than you need to turn it over to a wildlife center. Feed the baby bird either bugs appropriate for his size if he's an insect eater- usually meal worms or if he's a seed eater than something like kitten chow soaked in HOT sugar water for an hour or so should suffice until he's well enough to go out on his own and get his own food. But if you don't know what type of bird it is and what to feed the baby than it's cruel to try and do it yourself, and a professional should handle it.

Read this here, very helpful stuff: http://www.2ndchance.info/insecteater.htm

baby birds get their moisture from their food until they are old enough to fly and then drink water on their own.....feed the bird 3 or 4 large night crawler worms 4 times a day until it can fly

Nooo never ever feed a bird