Like @vchernobyl said it's very accessible. I would like to add that I'm subscribed to https://www.reddit.com/r/flutterdev. Everything from tutorials to news gets posted over there.

Just today I found this app which is great reference once you are aware of the basics

https://play.google.com/store/apps/details?id=io.github.x_we...

It's very accessible for everybody! The official documentation is excellent and covers you from a to z (UI, Networking, JSON serialization, etc). It gives you a strong foundation on which to base your application and exposes you to a few recommended application architectures (for example Redux and BLoC). If you're interested in mobile dev, it's definitely worth giving it a try :)