Did you download a language profile from the link in the documentation about language profiles after installing voice2json?:
The language profile is the folder whichs path you have to enter in the config. This is one of the major principles of voice2json. All the data that belongs to each language comes in downloadable profiles so you could even have more than one profile for the same language on one machine. To use it you will have to first extract it as it will be a tar.gz compressed file. Than you need to do an initial training before you can start with any of the examples. I really recommend you read the documentation about the config node most thoroughly next as that is the most complicated part. Your voice2json installation looks good 
