I need to build again my family tree

I can't figure out what happened but I suggest you post in the Public Discussion that is expressly for asking for help from volunteer Geni curators: https://www.geni.com/discussions/192543

It looks to me that you tried to delete things and that resulted in all the {No Name) profiles.

There are two ways to delete profiles -- in Profile View from Actions and in Tree View there is an X in the upper right corner of the rectangle / profile.

The problem is you have to start at the children and delete up. Maybe go to Help below and read about deleting profiles.

Looks like a bad GEDCOM import, I suggest you just close your account and start over again, but wait until the Geni engineers have had a look on it.

Tagging Customer Service to follow up, - I suspect that the GEDCOM importer did not handle the alfabet / character encoding.