When starting a business, most people start as sole proprietorships. If you live in Ontario, you can register your business name through Service Ontario, either at one of their kiosks or online. The registration fee is $60.00 as of today’s writing.
If you expect your business to incur debt as part of its operations (for example, you would regularly purchase of inventory or equipment on credit) or your industry is known to be highly litigious (i.e., there may be a good chance you can be sued someday), then you should consider incorporating your business.