So - would you like to play with Node-Red for free without even running it on your own PC? Check out FRED. You just don’t get any easier than this!
Also this morning I stumbled across KODING – an online programming environment for HTML, PHP, PYTHON etc. I don’t have any great expertise at this yet but I did notice that you get a full VM for free or so it would seem, with full root access. If you want to mess around with Linux commands without messing up your PI – could this be a good start? Certainly on my Windows 8 PC it all looked good. Not tried it on the Android tablet yet.