Codeblocks is a open source project, build by many volunteers, mostly experienced coder. For them most of the ui is self explaining, because it is the same for all C++ IDEs (i came a long time ago from VS6 (good old times) and learned everything by try and error). Codeblocks is developed in free time, and there is simply no time for writing documentation. You can help by start writing it

The wiki should be editable with the forum logins. If not please ask here for access.
The problem with english: I don't think that at the moment is one dev here who speaks native english...
You don't have to know every menu item to work with codeblocks. And if you have a problem just ask here. If it is a codeblocks related problem we will help you, if it is a coding error please ask on a c++ forum.
The most basic steps are described here:
http://wiki.codeblocks.org/index.php/Creating_a_new_project and
http://wiki.codeblocks.org/index.php/The_build_process_of_Code::Blockshow to create different versions of a program using codeblocks, so that i can test out each version separately.
This is a philosophical question:
1) If you ask for different versions of the same program, use a cvs like git or svn. Manage your code with it and as soon as you focus codeblocks it will detect that the code has changed and will ask if you want reload the code/project. Hit yes and all is fine.
2) If you want to have multiple main functions (different programs) then there are two main approaches:
2.1) Use a separate project for each program. This is recommended for beginners because it is the easiest way and does not have any complicated steps. You select the active project by double clicking on it in the Management/Projects panel (it will get Bold if activated).
2.2) Use separate targets in one project for every main file and activate only one c file per target. This is a bit complicated:
1) Create a project
2) Create your main.c/cpp files
3) Project->Properties->Build Targets
3.1) Hit the "Add" key for every main.c file and select at the bottom "Build target file" always only one main file.
4) Close the dialog and select your build target in the drop down menu near the build button in the toolbar