Ah, por cierto. Estoy trabajando en PC, no en Mac. Con Windows 7.
The Tutorial Links Page http://forums.adobe.com/thread/1275830 may help
Premiere Elements FAQ List (2 pages of FAQ as of September 2013) http://forums.adobe.com/community/premiere_elements/premiere_elements_faq?view=all
Premiere Elements TIPS List (6 pages of Tips as of September 2013) http://forums.adobe.com/community/premiere_elements/premiere_elements_tips?view=all
It is not clear how far into the program you are getting so please detail further.
Are you downloading Premiere Elements 12 Windows tryout from Adobe?
If so, do you go through the download and installation to get to the dialog which asks whether you want to buy or Continue the tryout?
If you get that far, are you clicking on Continue tryout?
What happens next? Can you open a new project? From what you wrote about Movie Menus, it sounds like you are in an opened Premiere Elements 12 Windows project if you can see the Movie Menu display of choices. With Premiere Elements 12, like version 11, much of the Content needs to be downloaded for use after you open your project and make your Content selection for Movie Menu, Title Templates, Instant Movie, Audio. This is true for the tryout and the purchased program. But, the program comes with one complete Movie Menu, that is, Slideshow/Pan and Zoom. Are you having problems with that one also.
Lot of details for you to clear up. The first one is what do you mean by activate the Timeline? More after that.
Please review the above and then we can decide what next.