The best thing you can do for it is to put it in a small, dark box an a quiet draft free area. That will prevent it from injuring itself. DO NOT offer food or water! Sometimes that can do more damage than good. Find a local nature/rehab center of some sort and take it to them immediately.
Keep the bird in a cage which has enough light and airy,keep a bowl with little small size grains. Keep a small bowl for water.Donot forget to place a waste plastic tray under the cage to remove the droppings.If mother bird is there don't do anything.
You keep the baby dove in box or cage.you should keep the box warm .You can keep the heat lamp or heating pad.if it wants heat you can keep the pad. it should be cover half of the cage.you can give grains and water hand feed method.
The most important thing to start with is keeping the baby warm. Doves do not gape like other birds, so food, such as Exact, must be tubed carefully into his crop, making sure not to get any formula on his feathers.