Someone posted "Methylene blue or malachite green are the appropriate anti-fungal solutions for eggs as opposed to melafix or pimafix."
Methylene Blue is anti fungal.
Malachite Green is anti bacterial.
As to food, micro organisms on a mature sponge filter or plants are a great food for cory fry.
For convenience, finely crushed slake food will help.
Hikari First Bites is readily available and very good. Golden Pearls is wonderful and you'll have it for the next batch. Cylops-Eeze is another man made food that is fantastic.