It's a bit difficult to learn GE from online C tutorials, since the way we write code into GE is slightly different from writing plain C code (We don't use #include, printing functions, a main() function, etc). If you're going to learn from an online source, you'll need to be able to separate what's going to be useful to you in coding for GE and what's C basics. There's a lot of things in C which aren't needed for writing
useful code in GE, and many tutorials for C are very wordy on these topics, while barely explaining things like structuring IF statements. It's probably a good idea to, yes, search on google for a source for your programming. There are lots and lots of places that try to teach you different programming languages, and any of them will work for the basic structure for IF's and FOR's and what-not. It's mostly up to your own brain about which tutorials way of explaining you prefer most.
Your best bet for finding out how all of Game-Editor's functions work and what the variables are are in its own
Script Reference. I did
a giant list of C keywords and how to use them in GE myself; it's not terribly well done and I made it when I wasn't as experienced as I am now, but may help you anyways.
A good thing to do is to get in closer contact (like instant messaging over Skype, for example) with someone who already can code C in GE fairly well (like myself, sky, etc) and ask them the questions you want answers to, since it's a lot easier to get things done when you can quickly respond.