Karlie here from the Shopify Support Team! Great question! There are multiple ways to have your customers search for products through your online storefront. Your first option would be to manually adjust your theme coding to allow your customers to filter your collections with product tags. We have a detailed guide, here, that you can read through to help you with adjusting your theme code.
Your next option would be to use an app. Although there is quite a large variety of options in the Shopify App Store that would provide you with a product search filter, I specifically would recommend checking out these options as they seem to provide the feature you're looking for;
I hope this has answered your question. If not, or if you have any further questions please let me know. I will be happy to help!