Hope you're having a great day!
All this is already taken into account natively by the themes of the Shopify store. You don't have to do it again. Which one do you use?
Here are some screenshots to help you get it effectively:
On your online store admin, go to All products > and choose a product
I understand where to edit the SEO within shopify admin. Let me give a little more information. I hired an SEO company to update our SEO. When I asked for details of specific changes, they claimed that they altered the shopify theme code to dynamically change titles/description upon render and not within the database.
I don't think this is possible, and was hoping for confirmation from an expert.