Joomla - pass variables via custom URL query string

I have a very quick project. The final deadline for this project is January 17. I have a page on my website that I would like to customize, so that when someone arrives at this page, using their personal QR code, the first line of text on the page will greet them by name. There are a couple dozen customers, and I do not want to create a couple dozen different landing pages. I am wondering if I can include their first name in the query string and have it display on the page, such as: If the query string is [login to view URL] The page would read, "Hello, John!" Our new website is a Joomla site. I am not familiar with Joomla, so I do not know if this can be done easily.