Once you have bought your Dynamics 365 CE subscription or set up a 30-day trial, you need to change the behavior of Dynamics 365 CE based on your requirements. Dynamics 365 configuration refers to the settings that can be changed using the Dynamics 365 CE application itself. We don't need to use any external tools to configure these settings. All of the system-level configurations are done from the Settings area. If you are using the classical web client interface, then you can navigate to Settings from the top navigation bar; but if you are using the Unified Interface client, then you can navigate to the Settings area using the Advanced Settings options, as shown in the following screenshot:
Keep in mind you can only configure settings if you have the required permissions. You need to have a System Customizer or System Administrator...