The best way to learn how to use PALAIS for your project is to go through the tutorials listed on this page. To get started grab the latest version of PALAIS from here.
Note that these tutorials are meant to ease your adoption of PALAIS by giving you an overview over the workflow of creating your own projects. As such they will only introduce you to the concepts of PALAIS. You can consult the documentation for more thorough description of the features of PALAIS.