GameMaker is made for people with no or very small background of programming/coding/scripting.
It is designed to handle everything for you and let you do only the "game" itself.
If you want something that you do code-wise completly, then gamemaker is not what you are looking for.
There are many other game making engines, one that comes to mind is the haXe ( pronouces hex ) which
is a Game-Oriented programming language, and it's open source and free.
Otherwise, if you stick to GameMaker, which is actually a lot less pain, you'll have to learn to work with the gui,
remember that the events are graphical components and not script-accessible, etc.