Generally, you, as the instructor, are responsible for building in the accommodations - granting more time on quizzes, adding attempts, adjusting font sizes, etc.
Canvas includes a product from Microsoft called Immersive Reader. It truly rocks! Your school will need to enable it in your Canvas account. I would suggest talking with your school's Canvas Admin. These guides will help you and your students get familiar with this new tool:
If you have further more specific questions, I or someone else in the Community will gladly help out!