Hello Rookie - Are you trying to add a SOAP Web service to the Data Sources list?

If so, follow the step by step shown in the article below:
https://support.office.com/en-us/article/Add-a-SOAP-service-as-a-data-source-638dd2db-e4e8-4279-809c-e9b785c36312

Also, please note that InfoPath is depreciated, that doesn't mean we can’t use it, we still use it in our company but if you have an option try moving into some other forms (Like Nintex)

If you are using SharePoint online (office 365) version, the suggestion provided above will not work, let us know what version of SharePoint and InfoPath you are using.

Hope this helps!

Thanks,
USNP Global IT Solutions, LLC