As seaman said, the settings for junk mail in Outlook 2013 can be found on the Home tab. look for the "Junk" drop down in the "Delete" area of the Home tab bar.
You select "Junk Email options..." to get to the settings for junk email.
By the way, mine was set to "No Automatic Filtering" which only moves mail from blocked senders to the junk folder. I changed it to "Low" to "Move the most obvious junk e-mail to the junk e-mail folder."