Help i have a african dwarf frog!?

ok so i just bought 1 at walmart and i dont know what to feed it i only have fish flakes will he eat it? and how often do i feed him?should i use a filter in the tank or is it fine like that the tank is 1 gallon. how many flakes do i feed it? any plants that i should have? how many times do i have to clean its tank? can you put rocks at the bottom?does it need light at night or day? how do i keep the water warm? please tell me anything i should know about it i have no clue! oh and do they sell food for it at petco?