During your time as a student, much of your experience with written documents has focused on secondary articles, that have been written from primary documents, and literary fiction. Primary documents require more observation and discovery on your part.
This tool from the Library of Congress wants you to start with the obvious, asking what you observe about the document, and then move into reflection and questions about the document, the time period it is from, and further questions you might have. This process can help you as a historian pinpoint the questions you may want to ask about the time period about the document.
The video below works as an example of how to use this tool to work for your Archives paper.