I decided to keep my reddit username (for old times' sake). For those making their way over, lemmy.ml is very busy right now; I signed up on lemmy.ca and had no trouble getting my account created. If I were smarter, I would find a way to do this from mastodon, but...
I just signed up tonight. I tried to log in about an hour after signing up, and it worked. Now I have to see whether I can find a community that lives elsewhere on lemmy.