Browse communities here: https://lemmyverse.net/communities

When you have found one you are interested in click the click to copy button.

Let's say for example you want to subscribe to "memes@lemmy.ml"

When you click to copy, "!memes@lemmy.ml" will be copied to your clipboard

In your browser enter https://kbin.social/m/community@instan.ce

So in this example it would be https://kbin.social/m/memes@lemmy.ml

Then hit enter, and subscribe!

I believe that the numbers that show on kbin are the number of kbin users that are subscribed vs on lemmyverse, its the number of subscribers on that (home) instance.

And lemmyverse is behind the real number because it syncs every x minutes.

https://kbin.social/m/cars@lemmy.world

Edit: this may take a minute to federate, but you can see it here in the search results https://kbin.social/search?q=cars%40lemmy.world