The Oxygen Section element by default does not have options for setting margins. But you can easily add margin in the Section settings in the Advanced > Custom CSS tab.
If you need to set up a unique margins for one specific Section, then the CSS code must be added for the ID:
The screenshot above shows an example of adding a 20px top and bottom margin. Specify the value of margins you need.
If you need to add the same margins for several Sections, then first add a class for the Section, and then add a custom CSS for this class:
Then add this class to all Sections that need to have the same margins. Simple, right?