I think that backup and restore will work for you.
I have created a set of template courses which I use as the "base" for all new courses. This is a good option when you want something a little different from the default blocks that are set in the .php files that run Moodle. You can have different "flavors" and use them at will. I use the backup files stored in the template course and restore to a new course. Then you can put in the distinguishing information and assign an instructor.
If you want to put template content into an existing course, it might be harder. In general, you can restore the template into the existing course and append it to the course instead of creating a new course or replacing the course (existing course, deleting it first). The tricky thing about that is to make sure that your topics are aligned. If you have some content in the template that needs to appear in topic 2, for example, it should be placed in the template's topic 2, even if template topic 1 is quite empty! And of course you can control exactly what you append by using the checkboxes. In the end, however, you might have to move some things around. Appends, if I remember correctly, place the new content at the bottom of the topic. If you want it somewhere else, you might have to move it.
I recommend that you create a category for your templates, or work from the backups stored IN the template course as a "space" to store, restore, and work on these template courses. It is really a bad idea to use the files area on the main course for your moodle site! You can make a mistake with your mouse and cause all kinds of trouble! (I should know, since I wrecked our front page
about 5 times when we were first learning to administer moodle!
Bless my sysadmin's long-suffering heart.)