General Calathea Care Tips:
Light: Bright indirect sunlight.
Water: Keep soil evenly moist. These plants prefers moist but not soggy soil.
Humidity: These plants love humidity. A lack of humidity can lead to a lot of issues, including crisping leaves and a higher susceptibility to spider mites. You can increase your humidity with a humidifier, misting the plant, keeping it in your bathroom (so long as there is enough light), or by placing it on a pebble tray.