I recommend that you spend time on the JMP Web site. There is a menu item at the top of the home page, Learn JMP, through which you can access any one of many resources that we made to help you learn to use JMP. Another area for learning is the Discovery Summit site in the Events menu. For example, the keynote presentation by John Sall during the past few years will give you some insights.
Are you teaching a statistics course? There are several sections that are devoted to instructors. Some of the material could be off-loaded as assignments for your students.
I agree with you that, at version 15, JMP is complex and sophisticated. Some of its best features are not obvious. A lot of learning and adopting a new tool is your mindset. For example, I teach JMP and lot of new users see a JMP data table and think, "It's just another spreadsheet." That starting point is where the frustration begins. (I am not saying that was your initial impression, but it is common. BI think that you appreciate the difference between statistical analysis and spreadsheet analysis because you use MINITAB.) The resources that I mentioned above are intended to reveal the JMP mindset so that it makes sense and you can quickly anticipate how JMP will help you solve a new problem.