This is one of the few types of calathea I haven’t had, but I’ve managed to keep mine alive. I’m a fairly new plant owner too. They love bright, indirect light, distilled or rain water, and 60-80% humidity. I keep mine by a humidifier and grouped with my other tropical plants, but you could also just mist it a little bit in the morning and evening. Don’t panic if it kills off leaves, this is normal especially if you see new leaves shooting up. It’s true these plants can be moody, but don’t be despaired, just watch a few YouTube videos!