That sure looks like a young baby! I don't have experience with babies, but it looks so young that it doesnt even have all it's feathers yet. This bird needs to be fed often (formula) so you need to get it help ASAP. It looks ill as well. You said you FOUND it? Where? How? Please give some details as to how you came to have this bird. Did you buy it after finding it at a store, or did you literally 'find' it?
Please take this baby to an avian vet ASAP, or contact a breeder, or even a bird store or rescue. Someone with experience needs to finish hand feeding this baby, to get it to at least eat and get it to thrive. Not sure where you are in the world, but if it is daytime, please get help now! Waiting any longer can mean death to this chick. Keep us posted too!