Therefore I’m absolutely confused and don’t know what I need to my program - Confluent Cloud or OSS Kafka. I have installed to my server both and currently I need understand way to going forward. Can anybody give advice to me?
You can connect to Confluent Cloud or OSS Kafka (installed locally or by running Docker). You can connect to either one if you use a client that supports the Kafka protocol (which the .NET clients do). From the .NET client point of view, there’s no difference between the two.