This is only required if the instance has never seen the community before. You can read how you can accomplish this in the Lemmy docs or the Fedecan guide:

Is doing above only for lemmy instance admins? Or is this for regular users? Thank you for the extensive write up, btw.

We believe in nothing, OP. Nothing!

Also a reddifugee, is there something we need to do to interact with the whole of Lemmy instead of just the server you registered on? (link please?) TIA

It’s been my experience on Reddit that you only ‘win’ a difference of opinion by not engaging people. And what you “win” isn’t Internet clout, it’s your sanity, continued semi privacy, and peace of mind.

Curious to see how Lemmy works out. Searching for a place you can actually engage in respectful disagreement or exchange of ideas. Even if someones’ ideas are different than your own, they help you think and explore, and if you come to the same decision, cool.