"Chicago style" comes from the Chicago Manual of Style (CMOS) and is actually three systems: Chicago author-date (similar to APA), Chicago notes-and-bibliography (a little like MLA), and Turabian (a simpler CMOS.) Use the one your instructor assigns, or the one favored by the field in which you are writing. For a basic guide, look at its website, https://www.chicagomanualofstyle.org/home.html. Or, carefully use the Chicago section of the Purdue OWL. Purdue University's very reliable Online Writing Lab (OWL) is now yoked to a profit-oriented company, so the website is cluttered with ads and video. Ignore them. Just use the basic content: https://owl.purdue.edu/owl/research_and_citation/chicago_manual_17th_edition/cmos_formatting_and_style_guide/chicago_manual_of_style_17th_edition.html
Below is a comparison of the two styles of Chicago style, taken from the CMOS website. The content is the same in both styles, but the format is slightly different. For in-text references, use footnotes instead of parentheses.
In the reference list, include the page range for the whole article. In the text, cite specific page numbers. For articles consulted online, include a URL or the name of the database in the reference list entry. Many journal articles list a DOI (Digital Object Identifier). A DOI forms a permanent URL that begins https://doi.org/. This URL is preferable to the URL that appears in your browser’s address bar.
In a note, cite specific page numbers. In the bibliography, include the page range for the whole article. For articles consulted online, include a URL or the name of the database. Many journal articles list a DOI (Digital Object Identifier). A DOI forms a permanent URL that begins https://doi.org/. This URL is preferable to the URL that appears in your browser’s address bar.