Hi,
In order to connect to product-ws and create the datasource, the recommendation is to use the servers which are associated with the On-Demand course. If the port which you are using is already used by some other applications then you could change the port in the start.bat file. For more information on changing the port, you can refer Web service module of the on-demand course.
For the training courses in Denodo 7.0, our recommendation is to use the Virtual Machine for doing the labs as the data sources needed are already available in the Virtual Machine.
If you are using own server, then you need to identify the port where the server is running and configure it accordingly, hence we suggest you to use the one which is included in the labs.
Hope this helps!