Report Builder is a additional permission that needs to be applied to accounts. I don't know if the administrators of that sandbox are going to open those permissions up or not...
One of the primary goals of providing access to the AA Sandbox is to showcase the in UI capabilities of the Analysis Workspace... since Report Builder is an add on which basically provides an API connection to the data and takes users out of the AA infrastructure, I would guess that this level of permission not likely to be granted. Also,
I don't know if the admins for those sandboxes frequent this forum.. did you just sign up for the sandbox directly, or did you do so as part of the LinkedIn learning course? You could try contacting the organizers of the course to get their thoughts on this request.
