Depending on the design theme that you may be using for your website design, your company name can be displayed in different places on your website pages; e.g., in the header, in the footer, in the main menu, etc.
Every design theme can use different settings values to display the company name. If you want to change it, check the following values in your backend.
“Site name” field in “Site settings” section.
“Company name” field in “General settings” section.
“Store name” field in “Settings” section.
“Appearance” tab in “Design” or “Storefront” section. Design theme settings may contain a field to edit the displayed company name.