I have created many courses which can help you along when you are learning Dialogflow.
In my Intro to Dialogflow course, I talk about the building blocks of Dialogflow (1) as well as the must know features of Dialogflow (2)
In the Dialogflow blackholes course, I talk about the features you should avoid (3) if you want to build reliable Dialogflow bots. The course also provides you a downloadable tool which helps you find out if you are making these mistakes in your existing Dialogflow chatbot.
In Dialogflow Conversation design, I discuss quite a lot of stuff which can be foundational (4) when you are building your chatbot. You will learn about how to dissect intent mapping (and sort of reverse engineer how it works), you will learn how to use contexts systematically to build more powerful bots, as well as some miscellaneous tips for building more robust bots.
In Dialogflow webhooks, I use some unconventional tools to help students learn how webhooks work (5). The important benefit of this approach is that you can avoid the somewhat confusing approach that is used to explain this subject in the current Dialogflow documentation. The code samples are in PHP, but if you can read PHP code, you should be able to adapt the learning quite easily to your programming language of choice.
In Dialogflow Flowcharts course, I show you how you can use XMind to create flowcharts for your chatbot (6). When you design the conversation systematically, it is usually half the job done and makes it much easier when you build the actual bot.
Dialogflow Bot Generators helps you create an FAQ chatbot from a CSV file. Dialogflow Navigator helps you search across all the training phrases, text and other channel (e.g. FB, Skype) responses inside ALL your intents for specific keywords, and also helps you filter on contexts and such. What makes these two apps possible? I spent some time dissecting the format of the agent ZIP file (7), and this helped me build these tools. In addition, the self-diagnostics tool I mentioned for Dialogflow blackholes course was also built to work with the agent's ZIP file.
Dialogflow REST API v2 is a systematic and thorough introduction to Dialogflow's REST API v2 (8). It also gives you an overview of Google's Identity Access Management, which will be helpful if you will be working with other Google APIs in the future.
If you are interested in my courses, my suggestion is to choose one of the course bundles. You get a fairly good price discount, and in addition you can also cover all the topics mentioned in this course.
The Dialogflow Toolkit bundle is an All-in-one courses + apps bundle which has all the courses and apps I have created. In addition, it is a lifetime price - meaning you pay once and get access to every single course and app I create in the future too. It has nearly 15 courses and apps as of this writing (Nov 2018). I will be adding more apps and courses through the next few weeks so you can expect the price to go up some more before 2019 begins.