You can see the delivery status of your emails by going to Tests/Campaigns > Manage Tests and using the Actions drop-down to select "View Scheduled Emails".
The "Send Training Page Link" will allow you to copy the link to the training page (or send a system email to the target that contains the training page link). Note that following the link to the training page will trigger a click action for phishing emails, and only applies to campaign emails that use training pages. Further note that the test must be active and the template sent to the target must have a training page for this option to be available.
If you see a green arrow next to the target's email address, as shown below, you will know the email has sent successfully: