Welcome to the Forum and to the world of programming!
To a complete beginner, you are a right, a lot of this will be quite daunting. But trust me when I say its not as hard as it seems.
There will be a lot of new concepts initially, but the beautiful thing about programming, is quite a lot of the languages are very similar.
On that note, I think it would serve you well to learn AGK's native language first (which borrows heavily from the Dark Basic language).
It will be quicker to learn than C++ and its less daunting. The beauty is, is that if you ever come to learn C++ in the future, you will realise that you only have to build on top of the knowledge you acquired when you learned Basic.
Although this is not AppGameKit, Daniel TGC posted a collection of video tutorials for Dark Basic Pro:
http://forum.thegamecreators.com/?m=forum_view&t=187474&b=7There is also a little begginners guide to DBP by Xenocythe:
http://forum.thegamecreators.com/?m=forum_view&t=64198&b=7While these won't give you direct help with AppGameKit, because AppGameKit is very similar to Dark Basic, the videos will hopefully give you a grounding into the principles of programming.
If you look through these tutorials, you should be able to see where AppGameKit hold similarities (If you look through the principle documentation) in AppGameKit Program -> Help -> Help -> Principles.
Also check the Examples page in the documentation. The general examples gives you the core info on program.
Hope that helped,
BiggAdd