Hi and welcome to LQ.
Just be aware that in LQ there are some points to understand, all cited in the
Site FAQ: Everyone here is a volunteer, not paid for support. We're here to help each other learn Linux, but this also means by guiding, not providing direct answers, therefore it is good to see your work. Homework is not entirely discouraged, so long as you do say this is what it is, and also to not please post the assignment verbatim.
In this case it would've been helpful for you to post a link to the tutorial question which you are having trouble with.
Please look up how to create a directory. This is a VERY FUNDAMENTAL command. I'm not trying to be rude by not telling you, I'm saying it is a very fundamental command and if you are completely unable to do the very simple thing of creating a directory, then you need assistance from your instructor.
That question is asking you to create sub-directories underneath the demo account. And then under one of those sub-directories, to next create some more sub-directories. All resulting in that tree.
If you cannot create "a" sub-directory at all, you need to do a general web search for something like "linux create a directory command line", or ask your instructor.