Historians typically use the Chicago Manual of Style for structuring bibliographies and footnotes. However, be sure to check with your professor to ensure that he or she is not requiring a different format, such as MLA. To learn the ins and outs of the Chicago style, visit http://www.chicagomanualofstyle.org/home.html and find the citation guide. Alternatively, you can use Purdue Owl https://owl.purdue.edu/owl/research_and_citation/chicago_manual_17th_edition/chicago_style_introduction.html. Both resources will be helpful to you, but I personally recommend visiting the Chicago Manual of Style website directly because it is more simple to navigate.
To get you on your way, included here are the bibliographic basics for the three most common types of resources: a book (with one author), a journal article, and a website.
A Book with one author:
Last name, First name. Title of Book. Place of publication: Publisher, Year of publication.
Kerouac, Jack. The Dharma Bums. New York: Viking Press, 1958.
A Web resource:
Last name, First name. “Title of Web Page.” Publishing Organization or Name of Website. Publication date and/or access date if available. URL.
Yale University. “About Yale: Yale Facts.” Accessed May 1, 2017. https://www.yale.edu/about-yale/yale-facts.
A Journal Article:
Lastname, Firstname. “Title of Journal Article." Title of the Journal Volume, Issue (publication Date): page range.
MacDonald, Susan Peck. “The Erasure of Language." College Composition and Composition and Communication 58, no. 4 (2008): 585-625.
These are three examples of a citation generator. Additionally, some of the databases you may have accessed automatically generate citations for you to copy and paste into a bibliography. Warning: These generators are helpful for getting you started, but they are not 100% accurate. Be sure to double check the formatting and punctuation.
It's a safe bet that your paper will also be graded on the accuracy of your citations. Don't take shortcuts and assume that Citation Machine, Zotero, or EasyBib got it right. They come close, but are not perfect and typically confuse the finer points. The mistakes most commonly made are incorrect punctuation, confusion over publication dates and how to format them (especially if a month and day are provided), and occasionally using the wrong structures for a resource (like citing an online journal article in website format). Be a responsible scholar and take the time to review!