Questions about export, edit, and type

Dear all,

I Apologize for my English.

Being a novice on Omeka, I have a few questions:

When I create a content type, I create new items, then I save ... And after saving the changes, I want to change the name of the items, how can I change without deleting and adding a new item?

Is it possible to have multiple types of content in a single item?

I want to export to CSV or XLSX, just the contents belonging to a collection, so I tried to download omeka-xml, but I do not see a dataset, is there a procedure to do? I tried PythonOmekaApiToCsv, but, it doesn't work.

Thank you,

Best regards,