Agile principles are few and the ideas are easier to adopt than Lean. You can start applying Agile Kanban without any change to your processes starting today. You don’t need organizational approval to use sticky notes, already in your office supplies budget, and a white board. If you don’t have a whiteboard, use a big window or buy a whiteboard wall adhesive, or buy an actual whiteboard or cork board. The deployment is simple and easy without many approvals needed. Scrum techniques of Agile can be added to your Kanban approach later if desired.
Lean principles are more involved. There are more of them, and how the principles work together dynamically may not be understood as well initially. After you experience some success with Agile, you may have more credibility to spend on convincing higher-level management that Lean is a good idea too. Lean sometimes scares employees who think that the leaning you’ll be doing is to headcount. Headcount reduction is not the aim of Lean. Deployment for Lean takes some degree of training followed by having your Lean-Agile coaches also coach Lean principle applications too.
Be sure you are clear that the Lean needed for courseware product development is Lean for product development, rather than Lean for manufacturing. Toyota has had great success with Lean for manufacturing, but you don’t need visual signals in a bin of parts, you need visual signals for knowledge work process steps like David Andersen pioneered.