My name is Lizzy. I'm one of the Gurus on the support team at Shopify.
To answer your first question, yes you can batch edit your products or variants, depending on what you'd like to adjust. This page here explains how to use various bulk editing options in the admin! You can select products to bulk edit or select variants in bulk within a product page. What sort of changes are you needing to make to your products?
You can also export your products to a CSV and make changes to them in there. Have you worked with CSVs at all in the past?
Would editing your products in bulk be an easier option at this point, or would it save time to delete? If deleting is the best option, you can do so with a bulk action. This recording here shows you how you can do that within the admin!
How did you upload the products you have in your store now? Were they manually uploaded or imported using an app?