String of pearls is a drought tolerant plant like most succulents. You need to make sure to plant it in a pot with a drainage hole and use potting mix suitable for cacti. When watering you will want to soak the soil thoroughly, then make sure to let the topsoil dry out completely before watering again.
Water: Let top soil dry out completely between waterings
Soil: Cacti Soil
Light: Bright indirect light