Hello.
I would start with the Out of the Box content. Login to PAM and click on the "Out-of-the-Box_ Content" link. This will install (if not done so already) the predefined content into your library area. Go to the Library tab and find the "PAM_PredefinedContent" folder. Start with "Getting started" and work your way down. Running the first "Hello World" process will have you running and completing your first process instance.
If you have not installed PAM yet I would start with the PAM installation guide in the \docs directory or use TEC607491 "Installing CA Process Automation version 4.2" available on support.ca.com. This will walk you through the entire installation and configuration of a single PAM orchestrator install.
Thank you.