Mentioned previously the default configuration will populate the MES Setup, however it is then down to you to change and manage the settings to best suit your business.
To open the MES Setup page use the search on the Role Centre.
Once on the MES Setup page you will see how each aspect of using the MES is split down into Different FastTabs. In each FastTab some fields will already be poulated and some settings will be enabled as part of running the Default Configuration.
The first FastTab is the General FastTab, there is only one field in here called Portal Fwk. Application ID, populated as part of the default configuration being applied. This field lets the MES Web Portal know that all settings below relate to this specific Application ID.