To see, as owner of the portal, the log of all the important events that took place on the platform:
Log in as the main Administrator of the portal
Click on the menu bar at the top-left corner
Select Activity log (1)
You now have a list of all logged events, available in chronological order (newer to older). Each event also includes the initiator of each action and the related IP information.
Note: You can also click Activity Range (2) to select a specific period for the related users' activities, and Filter Activity (3) to see just specific actions or events.