This site is currently struggling to handle the amount of new users. I have already upgraded the server, but it will go down regardless if half of Reddit tries to join.
However Lemmy is federated software, meaning you can interact seamlessly with communities on other instances like beehaw.org or lemmy.one. The documentation explains in more detail how this works. Use the instance list to find one where you can register. Then use the Community Browser to find interesting communities. Paste the community url into the search field to follow it.
You can help other Reddit refugees by inviting them to the same Lemmy instance where you joined. This way we can spread the load across many different servers. And users with similar interests will end up together on the same instances. Others on the same instance can also automatically see posts from all the communities that you follow.
Edit: If you moderate a large subreddit, do not link your users directly to lemmy.ml in your announcements. That way the server will only go down sooner.
Mostly correct. The only slight correction is that they can delete posts and block users from their own communities. So hypothetically, if User@serverone.lm posts starts being super rude on a community in servertwo.lm, then the admins of servertwo.lm can delete posts in their instance and/or block the user from participating there. That does not stop User@serverone.lm from participating in their own instance or any other.
The defederation thing is very much a last resort. If EVERYONE in serverone.lm is causing problems, and the admins of serverone.lm refuse to do anything, then the admins of servertwo.lm might decide it’s not worth the hassle to ban individuals and ban the whole instance.