Bank Street’s mission and credo are on this webpage. There is no author, and no date. Put the title of the page in the author position. Write (n.d.) for the date. Direct your reader to the appropriate section heading which in this case is Credo. Write the full URL.
Bank Street College of Education. (n.d.). Credo. https://www.bankstreet.edu/about-bank-street/mission-credo/
Cite in your text (Bank Street College of Education, n.d.). The author and publisher are the same, so there is no need to add Bank Street College of Education after the title in this example.