There's an O'Reilly AppleScript book that's pretty good.
The problem I always had with AppleScript is that it wasn't clear when I was writing AppleScript and when I was talking to an application's OSA dictionary (its "terminology" as Apple calls it in OSA).
Once I switched to Appscript (https://appscript.sourceforge.io/), that confusion went away. Of course I haven't used that in years since it's no longer supported and today I'd use JavaScript.
The issue though is that each application's terminology is isn't really documented. You can usually figure it out using Script Editor, but not always.
Some of this is documented here:
https://developer.apple.com/library/archive/documentation/La...