Would someone kindly tell me where the Scrivener templates are stored?
When you open Scrivener, you are usually greeted with the template chooser:
From there, you can select the template category in the side bar, which will give you a number of choices:
If you are not greeted with the template chooser when you open Scrivener, then in the menu bar click Scrivener -> Preferences -> General -> Startup, and make sure that the option to show template chooser when there are no projects open is ticked.
Open any project, then go to File>Save as Template - The popup window will show you where your templates are being saved. (Then Cancel out if you don’t want to save it as a template.)
On my system it’s: C:/Users/MyName/AppData/Local/Scrivener/Scrivener/ProjectTemplates
Remember though, you can’t edit a template directly. You have to open a project using an existing template, modify the project, then Save as Template to create a new template or overwrite the old one by using the same name.