Make sure that you only have one male per enclosure as males will fight each other. The substrate can be anything from sand to newspaper. Sand creates the most natural setup, and you can buy playsand from any hardware store. Rocks and logs can make the terrarium more natural looking and they provide your lizards with places to climb and get exercise. A hide box is also recommended for each lizard for use in times or conflict and for sleeping.
Leopard geckos are a nocturnal species so no form of UV lighting is necessary.
A simple spotlight with the appropriate wattage bulb can provide both daytime light and heat. Daytime temperatures should be around 90 and the nighttime temps can go down in the low 70s. I mean this should be the temperature directly under the spotlight. This will allow the rest of the cage to remain from anywhere to the 80's to room temperature. I feel that it's best to provide any reptile with a temperature gradient and let them regulate their temperature.