Add new course: from administration overview select "Add new course" from Courses menu:
Fill out courses data:
1. Label: your internal course label. This might be visible to students with smaller screens.
2. Course name: official full course name.
3. Other fields are not required at this stage.
Delete course: from administration overview select the course you want to delete using Courses menu or using "Search courses" feature. Then select "Delete selected course" from Ccourses menu: