Have fun with the geckos! I have some tips and info...buy from a local pet store.
Many breeders will rip you off and sell you sick reptiles. It has happened to us, so word to the wise. The pet store geckos, despite common belief, are often healthy and quite hardy. I've never had any health problems with my store bought geckos, but one female I got from a breeder and was very expensive died at a very young age. Now, here's the thing. Geckos can get boring. I do not mean to make any judgement against you at all, but many children lose interest in geckos within their first few months. They require cage-cleaning at least once a month and need mealworms once a day, or every other day for older geckos or breeders, a constant supply of fresh reptile calcium, a full dish of water 24/7, several hides, space, and at least two heat sources. I wouldn't start with three geckos if they are meant to be kept as pets. I know you don't want to hear this, but you need to go one at a time. First, a male. They are much less jumpy and nippy than females and very calm. He should get you acquainted with your gecko set up. Then, after at least four months of continued health, happiness, and interest, you *may* choose to add a female. No more males, they will kill or seriously injure each other. Then after your pair has been doing well for a year or more, it is possible you might choose to add another female, but oftentimes this will not be the case. To start off with your gecko, here is what you need:
A ten gallon terrarium, not tank, no five gallons for these guys.
A night bulb, which should be red.
A daytime bulb, which should be white/UV.
A food dish, water dish, must be easy to access and cannot be deep enough for the gecko to submerge itself, and at least three hides such as plastic caves, logs, rocks, etc., for shelter.
Calcium powder, made for reptiles, a couple boxes of mealworms or crickets, I recommend mealworms. The worms should be refrigerated, the crickets kept in a dark, cool place inside. Always buy gut loaded feeders.
Some sort of substrate. I start with carpets then move onto wood chips once the geckos are older. Do NOT use sand.
Finally, a heating pad. It must be kept at appropriate temps. It should be set under a hide as well as the substrate/carpet so it will not fry your gecko.
Now, feeding. Feed your gecko daily, usually in the evening or at night. Dust the live mealworms or crickets with calcium powder and put them in the food dish. Disclaimer, the crickets will not stay put. Watch your gecko to make sure he eats enough and with gusto. Make sure mealworms do not bury into substrate or under carpets. There should be no way for the insects or your gecko to squirm under the carpet and thus become trapped.
Water: Change daily, washing out dish every week to prevent algae growth and resulting mouth rot.
Cleaning. Clean the entire set up monthly, submerging everything in warm, soapy water. Then wash with cold water with no soap until suds are gone. Finally, dry throughly and set in the sun for at least fifteen minutes. Pick off any feces and scrub the spots hard with a sponge.
When your gecko molts: your gecko will shed its skin occasionally. This is a sign of good health. Let the gecko eat the skin and do not take it away. Leave a wet sponge in the tank so the gecko can run the shed skin off its toes. If this skin is not removed, the gecko can lose toes. Keep the sponge wet for at least seven days after the shed.
Ratios: never put males together. Males and females are fine, but expect fertilized eggs. Dispose of these wearing disposable gloves and a paper towel. Do not touch the eggs or any goop attached. After finding eggs, feed the female extra food rations, even pinky mice, to rejuvenate her strength. Keep in mind, lone females will still lay eggs, just unfertilized. Watch male for over mating.
If you have any more questions feel free to ask. I keep and breed leopard geckos and have had them for many years now. I'd be happy to give you ideas on which color morphs to choose and such. Good luck!