How to host font file?

I bought a font from Commercial Type. I’ve uploaded it to Webflow, and can see it in the designer—but I don’t know what to do with the CSS file. How do I host it? (I need it to change the font weight.)

Also, where does the font-face code belong? I’m assuming it’s supposed to be in the site’s head, but I don’t know. I’m new to all of this.