Baby frogs are generally fed pin head crickets or flightless fruit flies. Both can usually be found at pet shops. I know Petsmart has flightless fruit flies. However it is a starter culture and you will run out of flies quickly. You can buy larger cultures online (as well as crickets).

You can place an ad for them on here if you want to find them a new home. There may be someone local to you interested. Or you can put up signs at your local pet shops.