Hi!
There is a free version of soapUI that you can download at
http://www.soapui.org
Select soapUI, not soapUI Pro (which is not free).
In soapUI, create a new project and enter the URL of the WSDL of the web service you want to
test and sample request(s) will be created.
Fill in the parameter(s) in the request and send it. After having received the response, you can examine the response XML.
Good luck!