Answering to such questions is not a trivial task.
On one hand, you need no additional software/hardware to experiment with the CVI IDE if your goal is just to study the environment and CVI paradigms. You can look at the examples supplied in order to learn the fundamentals of the environment: they are designed to work without additional components.
The problems arise when you want to interact with external hardware like data acquisition devices and similar, given the multitude of different devices and interfaces. You could start by installing DAQmx software if you think you will need to deal with NI hardware: DAQmx (or better Measurement and Automation Explorer - MAX) permits you to define simulated devices with which you can experiment with setup and basic acquisition/generation functions. This product as well comes with its proper set of examples to study.
In order to go further you will need to define the scenario into which you will move and search for the appropriate hardware to work with.
