If the goal is to change the presentation, then the research needs to lean towards Qualitative analysis instead of Quantitative. Since we do need more information to decide the research method. Let's create an hypothesis around it.
In such a perspective and availability of users, time and schedule will decide course of action -
a. Diary studies - if users can be diligent and self-governed will provide insights after a week or two on set of questions put-up on questionnaire
b. Contextual Inquiry - Allow users to work on master-apprentice model with the designer or research. This partnership will provide to unearth key concepts and expectations from users to derive the method to present the learning section
c. Card sorting exercise - Though you will need to structure labels for the sections - there needs to be a logic to derive those 'labels'. Either these labels should be uniform across all sections helping users mental model or need to note the variation within the labels by building themes. Themes are derived in an affinity mapping exercise post collection of all labels and phrases.