Dear Garry and Utnik,
I really appreciate you taking the time to help me out. You might be right--I installed Scribus on a Windows machine, which didn't have the Avenir Next font, but substituted it with Arial, and the text displayed correctly when I generated a PDF file from the document. If using Arial or another standard font is all it takes, then I'll use that, not a problem.
What I'm left scratching my head with, however, is that the "Mindfulness Community" text in the top banner disappears in the PDF version, and am wondering why this happens. This is written in Arial as well. I've attached all of the necessary documents as an archive to make it easier for everyone.
I'm so happy to think that I'll be able to use Scribus! Almost there!