While we currently do not yet have a step-by-step tutorial specifically for XLingPaper, we do offer a Quick Reference Guide.

There are a set of tutorials for the XMLmind XML Editor tool that XLingPaper is based on. See https://www.xmlmind.com/xmleditor/tutorial.html

Also please check out the following two demo movies:
A tour of the XMLmind XML Editor that XLingPaper uses
How to type text in XLingPaper

In addition, you can read the documentation.