Tutorial?

[zdat]

I feel stupid but, how exactly do I do this?

I've read the how to use but I still don't know.

This isn't fully related to this, but Ideally I wanted to block all remote fonts on all websites and have my "locally hosted" (google) fonts take over, but I'm not sure if that's possible? I'm not sure how to "locally host" fonts. If that isn't possible, I would like to set this up instead.

Can someone tell me if I even have the right way of thinking towards this stuff? Thanks.