It takes 24 hours for student courses to reflect in Blackboard.
For your information, if you have registered for the course in the past day, please give the system 24 hours to add you into the Blackboard course. If this is not the case, please note that some Blackboard courses are made available to students by course instructors, in the first week of the semester, and some instructors will not use Blackboard at all.
If you have enrolled in the course more than 24 hours and do not have access to the course by the start of the semester, please let your course instructor know. Your course instructor will let you know if the course will be using Blackboard or not.