The Activity Feed is on the right side of the page.  This feed will show you activity information for the database you are working with.  It may be blank when you first log into ACP. This is because you have not selected a database to work with. 
You can also refresh the Activity feed by clicked the refresh circle on the right side. 
Remember, the information being shown in the Activity Feed is for the Act! database you are currently working with. The name of the database is displayed in the breadcrumbs.