I have hopped around a lot myself - @Blaze@reddthat.com is there a particular post to recommend reading in this regard?

My suggestion at this point might be to:

1. if you just want to read but not yet interact, log onto any one of them e.g. https://lemmy.world and poke around!:-)
2. consider if there are any particular communities that you are interested in the most - e.g. https://programming.dev/c/programmer_humor, or https://sh.itjust.works/c/patientgamers, etc.
3. for general-purpose ones - arguably the best approach - visit a site like https://lemmyverse.net/ to see those that have the most activity on them and might be closest to you.

Do NOT get mislead though by the community / instance descriptions, e.g. midwest.social says that it is for "leftists in the Midwest USA", but what it means by "leftists" is not the common usage (especially for people in the Midwestern USA, who would interpret it like "progressive liberal" or some such) and rather more extreme forms such as full-on communism. Similarly, hexbear.net never bothers to enforce their own Code of Conduct (the only time they remember the human is when you say something they agree with - any other time the human is fair game to be dunked on!). But it is like watching Fox News: regardless of what they say, pretty quickly you get a sense that something is a bit "off" when you visit these places:-).

lemmy.ml is much harder to get a read on though, hence the linked discussion. It does not say that it is leftist, or even has any instance description that I can see - they just call themselves "Lemmy" as if that is sufficient, with no disambiguation between it and the software that runs on it or any acknowledgement that the rest of the Fediverse exists. Ironically lemmygrad.ml is doing better these days at more accurately portraying what it is about, with a communist flag and manifesto - that honesty is appreciated, by me at least, as it shows an intellectual capacity to realize that other viewpoints exist and thus to distinguish self vs. nonself, unlike what lemmy.ml does (not).

I think there are some tools to transfer accounts but I have never used them so I don't know where to find them - sorry, but I hope knowing that at least helps you find them:-).