No worries, glad I could help 😀 To be honest, although the concepts remain the same, this article could likely do with a little updating.
With regards to what helped me when starting out. If I can’t gather what I need from the docs for a package, I tend to read code examples I can find and gather what I can from them. There’s also sometimes a lot to be gained from just jumping straight in and trying to put something together. I’ve found this on multiple occasions when trying to test various projects/scenarios. There’s sometimes a little trial and error to find the right formula for testing what you want to test but at the same time it can also be a useful exercise in promoting that you try and write testable things. Hope that makes sense! Started rambling 😄
Hope that helps a little! Feel free to drop a question anytime 👍
