Are you sure you have version 12? The Guided tab is right between the Quick and Expert tab in the top center of the interface.
Also, what is your monitor's resolution? It could be that it's not large enough to accommodate the entire interface.
Surely if you can see Quick and Expert, I would think that you would be able to see Guided which is right between them.
When you open your version of Premiere Elements, do you see the following?
If you do not see the above, could you post a screenshot of what you are seeing?
What computer operating system do you have your Premiere Elements installed on?