You don't need all columns.

Columns not provided will result in either a NULL value or a DEFAULT value, depending on the field.

Create a record via the UI and supply the same fields manually to see which other ones get filled in to know exactly. 

See also https://www.odoo.com/documentation/14.0/applications/general/export_import_data.html#import-data-into-odoo

You don't have to include all the fields, only those that are relevant to you and the "required" ones. 
You can see which fields are required by looking at the menu option (in debug mode) "Settings/Technical/Models".
The fields without assigned values will be set to "null" or to the default value, if any.