A course that is created is automatically assigned a default start date. If you would like your course to be available to students earlier—so they can, for example, do some preliminary reading before the first lecture you can adjust the start date.
To do this, follow these steps:
Go to your course and click on Course Admin in the Navbar.
Then select Course Offering Information
Scroll down and you will see Start Date and End Date. Here, you can adjust the dates to control when the course becomes available to students.
When you're done, click Save at the bottom.
Students can still see the course, but it is gray. You can read in this article how the students see the course