I have a upgraded to LR6 and am trying to use the slideshow module. But after searching I've realized that the Slideshow templates that are mentioned in tutorials are not showing up for me. Am I missing something?
You can try and reset the Lightroom Preferences to fix this Issue.
Follow the below location to find the Preference file for Lightroom:-
C:\Users\[user name]\AppData\Roaming\Adobe\Lightroom\Preferences\Lightroom 6 Preferences.agprefs
Once you see the Preference file, rename the file by adding .old in the file name.
Then, Open Lightroom and check the Lightroom templates in the Slideshow.