I found a bird in the street!? URGENT!?

Ok as you know I just found a bird in the street. I think its a Yellow Finch because it has a yellow and black body. I picked it up with gloves and carried it to my house and put it in plastic tubaware. I put some rabbit litter in the container and I read online that this wheat cereal thing ( Like oatmeal) birds can eat. So I'm feeding him some of that he took two bites. Hes lying on his back and his head his bent a little. What else should I do?