I am unable to find an answer online and as someone newish to Animate CC, reams of code are not helpful!
I have created a short 4-second animation (.fla) of a process on an HTML5 Canvas.
How do I best publish or export this so I can easily share it as a movie or animation with others? Or do I need to save as one thing and then find some kind of converter site online?
If your primary intent was to make an animation to share with people, you should have created an AS3 document, then exported it as a video file.
Canvas documents are little web pages, so the best way to share them is to post them and all their support documents to a web server.