Bringing all of your content (files, assignment submission spaces, forums, quizzes, quiz questions, etc) into a new Moodle class is very easy to do.
Moodle will import all of the resources and activities into the new, blank, class without importing any of the data (assignments submitted by students in the previous year will not be brought, the same forums will be created, but the discussions from last year will not exist, etc).
See the video below for the steps: