Open your Blackboard course by selecting it.  In this example, the lock icon and words "closed" let me know the course is not available to students.

Tip! If it says "Open" then your course is already available to students.  You can follow this same process to "Close" the course if you do not yet want it available.

Click the slider to de-select "Course content will be unavailable to students".

The Course Access indicator will now turn blue and show as "Open".

Your course is now open, as indicated at the top right corner.

Opening a Course in Blackboard