Close. It was a printed course I ordered from China via Taobao. Online courses for these things would actually be pretty cool though, now that you mention it… but I guess the problem with online courses is that they almost always inevitably end up somewhere outside the paywall, which is great for consumers, but not so great for authors. That happens a little less with stuff that’s on paper. I do know of a Japanese calligraphy site, but it’s for brush calligraphy. I guess you could still take a look at Takumi-san’s channel on YouTube though. He has quite a few pen calligraphy videos, even if they’re usually not tutorials.
Anyhow, I suppose I can’t recommend the course I used because it’s in Chinese, and on top of that, it deals with 行書, which is a slightly cursive form, whereas I think most people just want to learn the standard script (楷書) first. If you’re fine with ordering stuff online (because I know there are people who aren’t so comfortable with that), you can try getting a Japanese calligraphy course, I guess? Here’s one I think is pretty good:
I posted a few other links to courses on that page, but I sincerely think this one is the best if your goal is learning how to write well. It’s meant for primary school students, so I don’t think the Japanese inside is particularly difficult either, and it might even be good reading practice.