Sadly, creating or importing VMs does not automatically create interfaces:
and there's no CSV import for interfaces:
I did it by direct SQL import, but the recommended approach is to do it via the REST API, or python shell if you can get to grips with Django's ORM:
Version 2.3.0 recently added support for bulk object creation via the API:
You would have to create all the VMs in one call (to learn the database-assigned IDs), then create all the interfaces in another, and then all the IPs is another. AFAIK there's no way to import a 'tree' of related objects in a single call.
HTH,
Brian.