I think you have misunderstood the scope of the SDK.
The SDK does not provide you with the compilers or development environments for programming languages. The SDK merely provides you with information about TurboCADs programming interface to help you use those programming languages to create add-ons and utilities for TurboCAD. It also provides a variety of sample projects to illustrate some of uses that are possible.
So yes, aside from the VBA which is built-in, you will need to provide your own copy of Visual Basic, Visual C++, Delphi, or whatever other programming tools you wish to use.