I have to get it out of the way: do read the docs. 😄
If something confuses you, open an issue, as we're constantly improving them. We generally hear that people can get through them and feel pretty confident with Vue in less than a day!
Now to answer your question, I can't pick just one, but here are some great options beyond the free stuff you might find while Googling. A few resources that I've heard great things about:
- "Introduction to Vue.js" video course on Frontend Masters, by Sarah Drasner
- "The Majesty of Vue.js" book, by Alex Kyriakidis
- "Vue JS 2 - The Complete Guide" Udemy course, by Maximilian Schwarzmüller