Hi,
Each WSDL-based Service exposes a number of operations (conveniently named “operation” in the WSDL) that each have a request and response message format (both optional). In soapUI, the operations for a Service are shown as nodes under the Service node in the project navigator:

For invoking an operation you can add any number of request objects to an operation in the navigator tree. soapUI by default creates a sample request for each operation when importing, as can be seen below:

Hope this helps.