To use just storeUserConfig() you need to be connected to a WebLogic Server (for example the AdminServer)
wls:/nm/base_domain> storeUserConfig(nm='true'); Currently connected to Node Manager to monitor the domain base_domain. Creating the key file can reduce the security of your system if it is not kept in a secured location after it is created. Do you want to create the key file? y or ny The username and password that were used for this WebLogic NodeManager connection are stored in /home/weblogic/weblogic-WebLogicConfig.properties and /home/weblogic/weblogic-WebLogicKey.properties.
The error you are getting "NameError: storeUserConfig" indicates that the 'method' could not be found, are starting WLST by using wlst.sh (or .cmd) in this case the necessary classes should be loaded.
wls:/base_domain/serverConfig> storeUserConfig(); Creating the key file can reduce the security of your system if it is not kept in a secured location after it is created. Do you want to create the key file? y or ny The username and password that were used for this WebLogic Server connection are stored in /home/weblogic/weblogic-WebLogicConfig.properties and /home/weblogic/weblogic-WebLogicKey.properties.
in which weblogic.jar (probably) contains the necessary Jython modules needed to run storeUserConfig. As the default distribution of ' Standalone Oracle Http Server 12c' does not contain these modules it is probably not supported.
It's probably a little late for the original poster, but in case anybody else stumbles on this thread (like me today), I found a workable solution to this problem:
For a Standalone HTTP Server there exists in $domain_home/bin a command startComponent.sh or (on Windows) startComponent.cmd. This accepts as parameter the ComponentName which will typically be ohs1 and as second parameter storeUserConfig. Documentation on this can be found here:
Unfortunately this doesn't tell you where you'll find the config and key-File. However, on a second invocation I found that - at least on windows where I tested this - they get written into c:\users\<username>\.wlst so I'd expect them in the home directory on unix. After copying the files to a more common location, I was able to reference them the usual way (formatted for better readability):
Connecting to Node Manager ...
Successfully Connected to Node Manager.