You will get limited results if you try to search for "primary sources" in library databases since the Library of Congress does not use that subject heading. Try searching these subject headings instead:
sources
personal narratives
diaries
letters
documents
speeches
memoirs
You will get limited results searching for the word "autobiography" since the Library of Congress does not use that subject heading. Try searching for "biography" but then look to make sure that the author is also listed as a subject. That is your clue that the person is writing about him or herself, and that is a primary source.
Alan Witt (Geneseo's history librarian) is best reached by emailing him at witt@geneseo.edu. Ask for a research consultation, and he will work with you to set up a time that works for both of you, either in person or via Teams. He does have some limited offices hours from time to time, but email is the quickest way to get an appointment.