Hi, @SpaceGummy. Welcome to the Community!
I’m sorry to hear you are having trouble with the Printful app integration on your store. Since the app is a third party integration, please reach out to the app developers directly to have the issue resolved. They’ll be able to take a closer look at how it is interacting with your store, and fix any issues that are causing it to not connect to your products properly.
You can easily contact them via email by going to Apps from your Shopify admin, and clicking on ‘Get Support’, as seen below:
Alternatively, if you click directly into the app itself, there is also a live chat option on the bottom right hand side of the screen. It looks like this:
How is the rest of your store set up going? We have a set up checklist here, specifically for Print on Demand stores. I recommend working through it to ensure all the most important aspects of your business are taken care of before your launch day. Additionally, this blog post: Print on Demand: A Low-Risk Way to Sell Custom T-Shirts, Books, and More, is a worthwhile read for a greater understanding of this type of business model.
Hope you find this information useful. All the best!