Hey Matt2189,
The path you mentioned above just open the report designer and let you choose which template you want to edit. The best practise is to create a copy of the stock template in case you want to make some changes and in case you don't like what you customize you can always go back to the stock template.
For Estimates, there are different version of templates which are available in your account i.e Simple Estimate and Estimate (Custom).
You can also check these templates under Customers -> Estimates -> More Actions -> Customize Print templates -> Click on the drop down for Estimates to see the complete list. Once you add new templates through report designer, you can always change it from Customize Print templates.
I hope that helps!
-Inder