If you are talking about adding additional customizable fields to a product page then you need to code the product pages yourself.
See an example of customized product page here: https://support.wix.com/en/article/corvid-adding-a-product-configurator-to-a-wix-stores-site
That is what I was afraid of. That is way beyond my ability, and I can't get any WIX experts to even look at this for under $700.00. Thank you Sir! I am selling medical alert bracelets and I need 7 lines of customizable text.