IF, you added the individual/person (and, no other User/Patron has "Contributed" anything to that individual/person); plus, they did not ever/really exist; THEN, you should be able to "Delete" them from 'Family Tree" of 'FamilySearch'.
IF, you did not add the individual/person (or, another User/Patron has "Contributed" something to that individual/person); plus, they did really exist; THEN, you should be able to "Detach" (or, "Remove") them from YOUR "Ancestral" lines 'Family Tree" of 'FamilySearch'.
Here is a "Knowledge Article" in 'FamilySearch':
How do I delete a person from Family Tree?
I hope this helps.