I found a baby house sparrow how to care for it?

If you have a PetSmart or PetCo where you live, I would suggest going and getting some baby bird food because the same thing happened to me and the food was about 8 dollars for a jar of it... that way you don't feed it something it shouldn't have and it will have sufficient nourishment. And yes, I agree you should leave it in a shoe box in case it wants to fly.