Help with Stuffit, fonts, .sit files

I decided to install some fonts today. A couple worked fine. The problem is, I downloaded a .sit and when I clicked on it a window opened with a bunch of gibberish. I searched and found out I needed Stuffit, so I installed it. I opened the program, found the font file (not a folder, just one file), clicked expand, and now I still have a .sit file with a Stuffit icon next to it. It says it's an archive.

I've read until I have a headache. The Stuffit version is 14, it's the free version, I wasn't asked for a verification code or anything. I'm stuck..

You don't need Stuffit. You need Stuffit Expander. It's free.