Essentially, standard events are handled within the data mappings by selecting a variable and defining the value trigger. The value trigger is the value of the variable that triggers the Facebook Event.
For example, per the documentation, to fire a FB Purchase event:
1. I choose tealium_event as the variable in the data mapping to trigger the FB Purchase event
2. From my website, I know that when a purchase is completed by a customer, the value of tealium_event equals "purchase", so I enter "purchase" into the event configuration as my value trigger
In this example, every time tealium_event has a value of "purchase", a FB Purchase event will fire on the website.
In conclusion, the mappings you would use to trigger a standard Facebook Event depends on what you have defined in your data layer.