Hi, Do anybody knows a decent step by step, from beginners to advanced, actionscript ressources: videos or books? Do those old actionscript 3.0 books earlier than 2010 (2007/2008...) still useable for adobe CC 21.x ? Thanks in advance,
AS3 hasn't changed much in the last few years so the old books will help you to learn the language. Amazon has a lot of books on the subject.
You will need updated references if you decide to publish your app or game on Google Play or the App Store.
In both cases - language and publication - I recommend that you look for tutorials on YouTube, that you join groups and follow related accounts on social media, that you look for help on forums, such as the Starling forum, etc.
Here are some references that may help to get you started: