Can we assume that you are running Premiere Elements 12 on Windows 7, 8, or 8.1 64 bit computer. I will assume that for now.
After you set up the Premiere Elements 12 project correctly, there are numerous export choices, export to file saved to the computer hard drive as well as burn to disc (DVD-VIDEO on DVD disc, AVCHD format on DVD disc, and Blu-ray disc format on Blu-ray disc).
In Premiere Elements 12, the exporting is the section of the program named Publish+Share.
The choices under Publish+Share are
Private Web Album
Mobile Phones and Players
You need to explore what is there and what you want to do.
Let us focus on the Computer choice. Under Computer, you will find
Adobe Flash Video
Many do not see beyond the first three in the Computer list, because they need to use the scroll bar to the right Adobe Flash Video to see the rest in the list. Another to get at the rest of the list without using the scroll bar is to select Adobe Flash Video so that its panel turns blue. Then use the down arrow key to move down the list.
In Premiere Elements 9.0/9.0.1, the exporting area was named Share. In version 12, it is called Publish+Share. You should have no problems. In 9.0/9.0.1, you had the Timeline view and the Sceneline view. In 12 the counterpart workspaces are Expert and Quick. You can be working in either of these or Guided Expert or Guided Quick. Try to stay with the Expert workspace since I believe you will see better what you are doing and thus have more control over your projects.
Some reading material for you:
Premiere Elements 12 Help PDF
Elements Organizer 12 Help PDF
My Premiere Elements 12 First Look Blog Post
My Premiere Elements 12 Daily Discoveries Blog Post
Please do not hesitate to ask questions and ask for clarification.