It's very hard to raise a wild baby bird. If a bird has fallen from a nest or becomes lost from it's mother, you should leave the bird undisturbed for it's mother to find.
Raising baby birds, especially songbirds are very time consuming. They require special diets depending on their age and species. I would recommend you get in touch with a wildlife rehabilitator.
You should provide a comfortable home. It could be a cage that is enough for the bird's size.Supply enough food and water with vitamins to make it grow healthy even without the parents.
