If you have not activated your Accessibility Report, go to your course shell, and from the left side menu, click on the Settings tab. From there, click on the Navigation tab. Find the Accessibility Report on the list and drag and drop it on the top list of items to enable it.
Before starting to fix any files, please make sure you go to the Files tab from the left-side menu and delete any files that are old and you are not using them on your course anymore.
From the Accessibility Report, start with the content with the easiest issues to fix, which usually includes adding alternative descriptions to images.
Once you finish the content with the easiest fixes, work through fixing low-scoring files, which can include replacing scanned PDFs by downloading an OCRed PDF from Ally's alternative formats to boost your score.
Leave towards the end the remaining issues. If you need support with the remaining issues, check out the resources linked below, or reach out to our accessibility department to schedule an one-on-one session with an instructional designer.