It depends on how you learn best, Many people these days seem to be quite visual in their preferences and prefer video tutorials. And just a cursory review of these forums suggests that a lot people (particularly younger generations) are less interested in taking a structured, bottom-up learning approach than diving right in and doing things. If you want video, there are many good resources and most of them have sample tuts: Lynda dot com (a variety of trainers) , Ripple Training, Larry Jordan – to name just three names that often come up here. Vimeo has recently introduced a new, free course on the basics…I don't have any experience with it.
My preference was to work from the original Pro Certification book – then authored by Diane Weynand – now by Brendan Boykin. So I read about the basics first (the terms, the GUI, the workflow), section by section, and did the practice exercises with he sample material that comes with the book.( I also participated in a pro labs series that the local Apple store offered.) In my case, I was not under any deadline to switch and indeed was not entirely convinced I wanted to for the first several months.
The leading contributor on this forum, Tom Wolsey, has a site with a range of learning resources - some free and some paid.
You are, no doubt, a very quick Avid editor. So one of the things you will inevitably have to deal with is how slow working on X will seem to you. The software itself is very fast, but it really does take some patience to make the transition from tracks to clips. Again, on this forum and other forums, it's not hard to find frustrated legacy Final Cut editors who are trying to do things the "old way" with the new software.
Anyway, you start with a big advantage: you already know how to create. Now you just need to learn some new mechanisms to achieve those outcomes.
Good luck.
Russ