Welcome to the
FHUG John.
I have started a new thread for your topic, because it is significantly different from the one you replied to.
That was an upload to Ancestry, whereas yours is a download from Ancestry.
Have you reviewed the FHUG Knowledge Base
Importing to Family Historian advice for
Import from Ancestry website which suggests it is often better to
Import from Family Tree Maker (FTM).
Maybe you have done that as you say you have Media attached to Sources, which cannot happen with an Ancestry GEDCOM.
You can bulk delete Source records as explained in the FHUG Knowledge Base
Delete One or Many Records.
However, I would advise you to take stock of what you have before being too hasty.
At least take a Full Project Backup before deleting anything just in case you decide you want it back.
Deleting unwanted Citations is a different matter and will need a list of all those without Media.
It may be better if we understood where all these Source Citations have come from as FH does not invent them.
They must have all existed in Ancestry/FTM before you exported the GEDCOM.