I have been doing ALOT of research lately, but based on what I know, I can tell you that you will need about 10 gallons per gekko. You can use chips, sand, newspaper, paper towels, and slate as a substrate, but be aware that chips and sand can cause impaction, which is even more prominent of a danger in younger gekko's. And then They need a hot side, and a cool side, so a heating lamp or a under heater will be good. They need to be fed once every day to every other day or sometimes every 3 days I have heard. It's also a good idea to dust the crickets and mealworms with calcium. They need freshwater every day, and need a "humid hide," which basically is a cave with a higher humidity than the surrounding area, and this can be a tubberware container with a hole in it for them to get into, and it has a moist substance on the bottom. And there should be a hiding spot for every gekko.
That's about it off the top of my head. And if anyone with more experience than me wants to correct something, go right ahead.
The only difference between the animal and the human, are the letters that they are spelled with.