There are three primary course bundles which are suitable for people learning Dialogflow.
Learn Dialogflow ES
The Learn Dialogflow ES course bundle consists of multiple individual courses. I would recommend people learning Dialogflow ES to get this course bundle.
Learn Dialogflow CX
Learn Dialogflow CX is a single course and has all the material you need to learn Dialogflow CX.
All Access Pass
The Dialogflow Toolkit is a course bundle which includes ALL the courses I have created. Plus, all future Dialogflow courses will also be added to this bundle.
There is also a personal license for individual users , but it is primary intended for teams of 3 or more people.
You can get a $25 coupon by taking a small survey in the chatbot on the bottom of the page. See the full list of courses here