This course is considered a test/ practice forum, where you can experience adding/ removing/ editing activities, enrolling users, switching roles, building course blocks and changing structure of the course. you don't need to worry about adding or removing any activity within this course, since it's already created as a practice forum.. do whatever intelligent mistakes you can, to ensure that you are able to create your course properly in the near future. Kindly note that this course will stay open for a while so you can get back to it trying new options and activities free from any worries.