In the documentation, the following code snippet is used to create the jsonDoc:
var jsonDoc = new Object();
jsonDoc.name = "Nick"; //It can be anything like users first name
jsonDoc.type = "30";
Here the name is not the doc name, it is the extra info about the user in the key-value pair which will be saved for the user as follows:
This info can be accessed by associating the query along with the getUser API call as shown in the Fetch Additionla data code snippet.
Also, permssions on decoument created along with user creation is depend on the App permission which you have choosed at the time of App creation in case of ACL app. If its Public Read then all users can access this information from Storage Service, but they don't have rights to update it. If it is Public Write or All, then anybody can access and update that data using their session id.
If you don't want to provide access to read or write to publiic users, then you can simply call RevokeAccessOnDoc function from storage service and revoke the permissions. Please have a look at this link for the code snippet and let me know if it helps.