I think it'd be more effective to just tell them an instance to choose. If someone asked me how to pick a Lemmy instance, I'd say direct them to a large, general instance: "Just sign up on lemmy.world [or some other instance]; it's a large instance with good moderation, and you can figure out if you want to switch to a different one once you've gotten more acquainted with the fediverse." My idea here would be to just get them to try it out without lingering on the question of which instance to choose, as it doesn't really matter for newcomers when we're talking about large, general-purpose instances.