Though Service Portal comes with more than 30 Services preconfigured, it is likely you will want to create new, custom services for your custom processes. This is done in the Services section of Service Portal Administration.
There are two primary ways to accomplish creating a new Service: Cloning an existing Service or Using a Template. Service Portal comes with one preconfigured template to use: Request with Default Submission Process.
Note that all Services are to be created by starting with an existing Service or a Template because there are certain fields required for Service Portal to work properly. These will exist on any existing Service or Services created using the out of the box template in a hidden section called: Hidden System Questions Do Not Delete.
Regardless of whether you use the Service options to clone a service or the Create Service button to create using a template, the form is built the same way:
You set the Service Settings
You add the desired content to the form in the Form Builder
You configure workflow