Most important thing, if nobody knows of your community nobody can subscribe. And for that to succeed you really need to know how to link to it properly. askhistorians.lemmy.world does not exist. If anything it is !askhistorians@lemmy.world and not just in the title but in the post body so people can click it.

And maybe you should be coordinating with the people of !askhistorians@piefed.social to consolidate on one platform so subscribers aren’t split.