Hi Sarah,
It is not clear whether the application has been installed on your computer or not. Can you please tell me how did you install the CS6 version? If you downloaded it from the Creative Cloud desktop application, it would have been installed on your computer by itself. To confirm if it has been installed, please check if you see Premiere Pro CS6 in your Applications folder.
If it is there, try to launch it and let me know if you see the splash screen. Also, please specify more details about your computer like RAM, Processor and Graphics. It would be of great help if you can attach a screenshot of the problem.
Thanks!
Rameez