As an Admin, you have the ability to change the status of a session right from the top level summary screen. In most cases, your sessions will be Pending until all its resources are approved, at which point the session is deemed to be Accepted.
Changing Session Status (Inline Editing)
The easiest way of changing session status is via inline editing in the session grid.
From the Admin portal, click on Sessions > All Sessions:
Scroll or use search to find the title of the session you're looking for and find the Status column next to it. If you can't find the Status column, don't worry - you may just need to adjust your Session Summary View Settings.
When you click the Status, a drop-down menu will show a list of the options: Accepted, Declined or Pending. Select the appropriate status and continue editing on the page as needed.
When you're done with your edits, simply click outside of the Status field and click Save when you're finished.
Alternatively, you can change Session Status via the Session Gradings View (Admin > Sessions > Session Gradings View).