While I don't use templates. I have Premiere Pro and am teaching myself editing so I don't bother with templates yet.
But from the quick research I just did, Templates are generally video editor specific.
Google Templates and a whole bunch of companies come up.
I also checked out what has the best reviews for amateur movie makers.
It seems to be Cyberlink,
Which brings you to the products page with Canadian prices. Sorry
They have some cool packages from 69 to 129 dollars and all of them allow you to add to what comes with the software by downloading templates and other things from their site.
If I was looking for something simple but does a lot, I would buy one of them.
Like all video editors they have a free trial for their products.
Tha's my 2 cents. I think I might download a trial as some of the things it can do are more complicated with my more expensive editor.
I find if you google your question in various ways you can find a lot of information