Those instructions are generic and it turns out they don’t cover the case in which the file tree contains linux symlinks which point outside the tree you are archiving. Some of the DLS assignments do have such symlinks. The way to cope with that is to add the “h” option on tar, which tells it to “chase” symlinks. So instead of “czf”, try “chzf”. Here’s a local thread which goes into more detail.
Also note that if you are a newbie with the linux shell, then this is not going to be easy. You need to know enough about how to explore a linux file system to figure out if the terminal window you get happens to have a relevant “current working directory”. Not all of them do, so you need to be able to “cd” around and find the right subdirectory containing the assignment files.