What I need to be happy in your home:
Light: Place your Calathea where it will receive bright ambient light, and watch its leaves move up and down with the sun! Make sure to avoid direct sunlight though, as this will scorch the delicate leaves.
Water: Calathea prefer soil that is slightly moist at all times. If the top 1”-2” of the soil are dry then your plant is ready to be watered. If you let the soil dry out too much, you may see browning or yellowing on the leaves, but don’t fear, these plants are hardy and can bounce back after a good drink!
Amy's Tip: These guys like high humidity - try a humidifier or a pebble tray!