Everything I can recommend is in Chinese, so I don’t think it’s a good idea for me to suggest anything. 
I’m really sorry about that, but if you really want to know, it was a course by 田英章, a Chinese calligrapher, on 行书. (That’s how it’s written in Simplified Chinese). If you want to try searching the internet for resources on calligraphy, the word to use in Japanese is 書道（しょどう）, and the word in Chinese is 書法・书法.
The one course I recommended on writing in Japanese is this one:
(I mentioned it in the post I linked to above on the ‘Japanese writing resources?’ thread.) It contains lots of helpful stuff about how to make the basic strokes, kanji shapes and proportions, and so on. However, it doesn’t cover the semi-cursive and cursive forms. To learn about those, you need something else, like, say, a course specifically about one of those forms. I think the easiest thing you can do to learn about them without being able to read such a course would be to take a look at YouTube videos and pictures for samples. You should probably start with the channel I mentioned above, which I’ll repost here:
At the very least, a few of his basic videos are subtitled in many languages, including English. In actuality, if you learn how to write kana from his videos, you’ll already get a basic idea of how calligraphy flows, because the hiragana are derived from 草書. In order to fully understand what I mean, you’ll need to know how the hiragana evolved from their source kanji. I posted a video about that on a thread I created myself, which is here:
I hope that’ll help you to work out the basics and give you some ideas until you’re able to read calligraphy courses in Japanese. 