haw to get data from Cloudant (json document)

One way of working with JSON in .NET would be using Data Contract: deseralize a json string array[^].

If this is not JSON created in .NET using Data Contract, it still could be possible to create a contract matching the data structure. In all cases, you will need a comprehensive description of the data format/structure.

If this is hard to do, see also my past answers:
How To Convert object type to C# class object type[^],
how to conver multi level json data to C# Object?[^].

You can also consider using open-source 3rd-party product JSON.NET: https://json.codeplex.com[^].

—SA