Yes, you can do projects in C and in C++. Most compilers will recognize the source file by its extension, and adjust itself accordingly.
GDK tutorial websites are probably your best bet.
There is no such thing as basic C++. You probably meant standard C++, which simply means that the implementation conforms to some ISO standard. The current standard is ISO/IEC 14882:2011, informally known as C++11. However, simple projects can be created in any version of C++ by creating console programs.
b+b+b+c+c+c+c =3b+4c
c + c + 2c + c + c = 6c
WM_* identifiers are Windows Message Codes defined in windows.h. They really have nothing special to do with C++ projects, as they are a function of an implementation library. There are more than several hundred different message codes.
b + b + b + c + c + c + c = 3b + 4c
4c
c + c + c + c + c = 5 * c.
There are no "primary and secondary keys" in c and c plus plus.
3c
No, it does not. But Microsoft Visual Studio 2008 allows you to connect to a virtual machine and run your projects "sandboxed".
There is no such thing as 'unix C++'.