MOOOOO! I just made accounts today for both Yiffit and Pawb.Social. So far I'm definitely enjoying Lemmy as a Reddit alternative, and it's making it a lot easier to give up Reddit entirely now that I'm without my Reddit app of choice.
You can visit communities on other instances (servers) with an account from anywhere. As an example, I'm posting on this thread using my @pawb.social account, but the community is located on @yiffit.net.
There's a small infographic guide to Lemmy here, or a short text guide here.