Sorry if this reply comes late.
I am totally agree with Jenafer.
I think you could first check out instagram as there are many people posting their work on the course.
That would help you know much more about the course content as well.
I personally think taking the online course really requires your self-discipline. Whether you can really make time and space to watch the video and do your own practice. Although it has lifetime access which could be great if you want to pick up calligraphy again later in life, falling behind the preset schedule could somehow make you feel bad.
Most importantly, I think it is important to train your eyes through practices, to know what you what to achieve and critique your own work/ practice.
Just like what Jenafer said, there are many free resources here on the forum and IAMPETH.
There are also some very good videos on youtube.