To export an entire list:
Go to "Lists", in the top panel on your dashboard.
Hover over the list you wish to export and click on the 3 dot menu icon. Next, select the "Export List" option.
The file will be sent to your email address (or you can send it to any email address you would like).
Alternatively, click on the list you wish to export.
From within a list, you can either click "Export" to export an entire list, or select individual contacts to export.
Export a single contact:
From within a list, click the 3 dot menu, and select "Export Contact".