Google My Business Guide
Primary Category & Categories
Primary Category & Categories for Your GMB Profile
Your category selection is very important and does have an impact on local ranking factors. Your primary category tells what your Ottawa business is (Law Firm, Dentist, Plumber, Hair Salon, etc). It is also the only category that will be published publicly.
Use the additional categories to your advantage and be sure to add all of the ones that are applicable to your business. Check category options regularly as they are often updated and new opportunities may be available for your business.
Also step up your game and use this GMB category hack to find out which categories your competitors use: