Connect user input(ed) single page pdf files from database to repeater

I am creating a webpage that has a form where I ask users to submit some text data and also single page PDFs. I have created a page with a repeater on it and have connected it to my data…everything works great, except the document. In the file upload. Wix allows me to upload a pdf file and it appears in the database. What it won’t allow me to do is create a place in the repeater to put either an icon or a small preview of the pdf file. Here is a link to the site as it is. The Home page is not really ready, I just stuck in a few links to help.
There are some tutorials out there ie, “CodeQueenNayeli” that shows some detailed code to do what I think I need to do, but there is not a lot of explanation for what the code actually does and how to put in your code information.
Thanks for any help

So I just spoke with someone at Wix and they told me that what I am wanting to achieve can be done through code. I am just not sure in which direction to start.