They should be fed. Everyday, but not twice a day. 5 crickets per night is fine. You can also just start feeding him however much he. Will eat in 15 minutes, but 5. Per night is a good start. You should give him a varied diet so crickets/chuncks of nightcrawler. Occationally offer him waxworms/mealworms, but only one or 2 per week. Silkworms are an excellent feeder for frogs right up with the nightcrawlers and earthworms. Be sure to dust his food with a multivitamin once a week and with a calcium supplement that contains Vitamin D3 every other feeding.
It is. Ok to use a heat light. Fluorescents are usually too bright and do not release. Much heat. You should use incandescent bulbs combined with a. Lamp that has a dimmer switch so you can control how much light and heat is produced by the bulb. Fluorescents cannot be dimmed without a special dimmer. You should place a UTH(Under Tank Heater) on the warm side of the tank(on the actual side or back of the tank not the bottom). This will aid you in maintaining correct temps. Babies should be kept at 80 to 82 during the day and 75 to 79 at night, but hover around 78. Humidity should be maintained at 80%. It is fine if you remain in the 70 to 80% range though.
Substrate should be moist or heavily damp not muddy. Make sure that all water you use to exspand his substrate/use in his water dish/ and mist with is de-chlorinated water or natural spring water.
Any further questions just ask. There are several experianced keepers and breeders here to help.
Welcome to Frog Forum
PS) Read this
Frog Forum - Pacman and Horned Frogs - Ceratophrys - Care and Breeding
A lot of good info in there for you.