jointhefediverse.net seems to be a commonly linked resource for directing people to join the Fediverse.
Curiously, it does not list Lemmy under the list of Reddit alternatives. Their GitHub README explains why.
Previous relevant discussion: https://lemmy.ml/post/78808
ty for this post. Looks like a well-trod ground for most people here, but for newcomers like me the whole conversation was really enlightening and TIL.