The best practice is to use sans-serif fonts rather than serif or decorative fonts. Sans serif does not have decorative lines. The fonts would include Arial, Calibri, Century Gothic, Tahoma, and Verdana. The font size should be 12 pt—font for the body text. The font could be larger depending on the audience or page layout.
Open the Word document that you want to check for accessibility.
Select the "Review" Ribbon button.

Select the "Check Accessibility" button.

Review the results from Word.

Edit the document to make it easier to understand.

Microsoft Word will give you the steps to fix it and explain why the accessibility issue needs to be fixed. You can also find articles about fixing additional accessibility issues here Accessible Features Microsoft Word.
Errors are when the file is very difficult or impossible for a person with a disability to use.
Warnings are when the content is difficult for people with disabilities to understand.
Tips are when there is content that people with disabilities can understand but could be changed to be better understood.
To View and Listen to a Video Tutorial:
Select the link below to watch and/or listen to the tutorial:
How to Video for Using the Accessibility Checker in Word (00:00:59)