Select the arrow next to a notification to expand it and see more, or select the notification to open the app (or other notification sender) it's from. Some notifications let you reply to messages or interact with the sender directly.
Want to see some notifications first in action center? Tired of seeing others altogether? Press and hold (or right-click) a notification from the sender, then select Make this group high priority to make it appear higher in your notification list. Or select Turn off notifications for this group to stop seeing those notifications. To make other settings changes, select Go to notification settings.