This is really about summer reading for AP Lang:
There is no required reading for AP Lang this summer because of covid-19. However, given that the class focuses on non-fiction texts, and you have likely not read/studied a lot of non-fiction texts in your previous English classes, it would be good for you to spend some time reading non-fiction.
You can find excellent non-fiction, of the type that we will be reading and that you will be tested on, in the following publications: The New Yorker; The Atlantic; The Medium; The New York Review of Books; The London Review of books. Again, you're looking for NON-fiction....so no stories, poems, plays, etc. Also, pick up some longer-form non-fiction: Biographies, science, sports, etc.
Here is the official course description from AP: (https://apcentral.collegeboard.org/pdf/ap-english-language-and-composition-course-and-exam-description.pdf?course=ap-english-language-and-composition)
"The AP English Language and Composition course focuses on the development and revision of evidence-based analytic and argumentative writing, the rhetorical analysis of nonfiction texts, and the decisions writers make as they compose and revise. Students evaluate, synthesize, and cite research to support their arguments. Additionally, they read and analyze rhetorical elements and their effects in nonfiction texts—including images as forms of text— from a range of disciplines and historical periods."
Please email me at email@example.com if you have any questions.