Hi, there!
I'm Shay, a Guru here at Shopify.
Happy to help out! Based on what you have said here, it sounds like your products have publishing errors, which you can view by logging into the Shopify Admin and clicking Facebook>Account. Scroll down to the Publishing section and you can see an errors section that will show you the products and the errors on those products. As soon as those errors are cleared up, your products will begin to publish on the shop! Our product requirements overview here: https://docs.shopify.com/manual/more/facebook/posting-products#requirements may come in handy!
Hope this helps, if you need anything else at all reach out to the Guru team directly, we’re here, 24/7 via live chat, phone and email. https://docs.shopify.com/support.
Have a great day!
Shay
Guru | Shopify