I saved a bird an don't know what to do with it.....?

This bird needs to go to a wildlife rehabber or vet that takes injured wildlife in. Many do and it is free. Any bird that has been caught by a cat needs meds as cats have deadly bacteria in saliva that proves toxic to birds in days. You may not see any injuries but many times there are puncture wounds hidden deep under thousands of feathers. If this bird is a fledgling that was on ground it may not be able to fly yet. A vet can refer you to a rehabber or the DEC can. Sooner the better. Keep it warm by placing in cage or box with heating pad under outside bottom of 1/2 of box or cage. Give food and water. Offer seed, meal worms, soaked cat and or dog food. Make the water shallow. Then get it some med attention. Good of you to help it. Maybe put a breakaway collar on your cat if it has to go out with a nice bell on it to alert wildlife of it coming. Good luck.