When another instructor made their course public and allows you to use a template of this course, you can create a copy of this course in your own account. You will only get the course content, and none of the course participants will be copied.
How to copy a course of another instructor
First the instructor should allow you to copy a template of their course. If they do not know how to do to this, you can share this article with them.
Ask the instructor to share the public course link with you
In the header on this page you should click on Use this template and the course will automatically be copied to your account!
Please keep the following in mind: the 'Enroll now' button will enroll yourself as a learner in this course. Only select the 'Use this template' button if you simply want to copy the course to your own account.