Peperomia are one of the Easiest Plants to keep alive.  It is almost Impossible to kill and will love you back with lots of new plants

They have Firm and Strong Leaves, if they feel floppy or soft, then the plant needs more moisture. 

Peperomia like Indirect Bright Light. They are perfect windows companion and for Houseplants. 

Watering

Water the Soil not the Leaves or Water from Bottom Up. Place the Plant in a well-drain Pot. Fill up a bowl with water, only quarter filled. Place the whole Pot inside the bowl, let the water sink in for 30 minutes. Remove the pot and let the plant dry out.

Only water when the Soil looks and feels dry. It might be around 7-10 days. Overwatering will kill the plants.