Configuration.Instance.GetItemConfiguration(AppGuidID, Kind.Camera, CamerasEncontradas[0].FQID.ObjectId);
If you use GetItem you will get the built-in kinds like Cameras. If you use GetItemConfiguration you will get Items defined by a MIP integration. So, in the context of the question you ask, using GetItemConfiguration does not make sense.
Trying to guess from your question what the best approach for you is, I think you want to see how a camera is configured. To do that you should use the Configuration API. I suggest that you as a first step explore the Config API Client sample.
PS. While as I mention I do not think you want to use GetItemConfiguration, if you want to explore a sample where it is central please see the Sensor Monitor sample-