Hi there @JenJones2! I can only think of one way to make it the left and right side split like you want, which would be creating a stimulus question in New Quizzes with an essay question. Not every school has New Quizzes enabled yet, so you may want to talk with your school's Canvas admin to find out if that would be an option. Additionally, it would be a quiz rather than an assignment, which might have some stressful connotations for some students.
If you can't do a New Quiz, you could still do an assignment and embed the article or attach a file of it in the assignment directions. Students would just have to scroll up and down on their page to switch between reading and their text box.
I do want to caution though, I would try to avoid having your students type a lengthy essay in the text box features within Canvas, whether it be in a quiz or an assignment. The students' work will not save in any way so if their internet goes out, Canvas glitches, the page refreshes, anything like that, the student will lose all of the work they have done and it cannot be recovered. It happens more often than you'd think and can be so upsetting for your students to have to start from scratch.
