Other types of files besides RenderMan and the DCC plugins can be downloaded with the installer as well. These include the PixarRenderMan-RenderMan Examples. These will be placed in the users Download directory.
If you plan to take advantage of the Python binding you will need to download Python installer from www.python.org. RenderMan Pro Server 21 binding is compatible with 2.7, 3.4, or 3.5.
If you require further assistance, please check out the RenderMan Support Forum. Note that registration is required.