It is also suggested to make your own set of templates and sheet formats and save them in a directory for your templates (leaving the originals in their default directory.
Then set your file locations to point to your set of templates and you can customize them as you want without changing the originals.
By leaving the originals, if you want to make another one later from the original you still have the master - untouched.
If you have a problem with one you updated you can go back to the original and re-create a new one for you.
A good thing to do is always leave the masters as they are and work off copies of customized copies.
And make a backup before customizing anything - especially when you are new to the software.
Your school should have a file location for their templates, ask your instructor.