Hello Ariel,
This depends, of course on exact scenario, that you have in mind.
However if you are speaking about general events, you can leverage either general object events (insert, update, etc) for each kentico object with appropriate handlers:
https://docs.kentico.com/k10/custom-development/handling-global-events/handling-object-events
Or you can create completely new custom ASP.NET events, raise them whenever necessary and handle events in their handlers:
https://www.tutorialspoint.com/asp.net/asp.net_event_handling.htm