Before importing, whatever it is, have a look at the document in the software it was made with. If there are any errors, they will be easier to correct in the text processor, first. Check some points at this time to clean the file and then import.
Before importing, have a look at the document. If there are any errors, they will be easier to correct in the text processor.
Delete all the empty lines (too many people do that but you will replace them with a space before and a space after in Scribus paragraph style).
Check that the styles are perfectly applied (display only applied styles), and try to remember where because it will be useful when you get them in Scribus.
Go back to Scribus. If you want to work on a new document, set it with automatic frames in the New Document window. Ours is set to A5 double-sided with six default pages, and a top margin at 20mm.
Then, select the frame of the first page and choose File | Import | Get Text or Ctrl + D....