The !askmeanything@lemmy.ca would be good, as would !asklemmy@lemmy.world or !casualconversation@lemm.ee. Also, I am going to gently push back on the idea that you have to make a new community because Reddit has a similar one. An AMA is not philosophically different from the posts on any of several other text-based-engagement communities. If AMA posts start to crowd out the "original" content, then a new /c is warranted, but we just fragmented everything after the APIpocalypse, and discoverability is still a pain requiring steps that shouldn't be necessary if people just want to communicate.
I had to look it up too, but it was Victoria. She was great as a celebrity wrangler to make sure they understood the vibe and would roll with the weirdness. I'm not entirely sure we need a Victoria just yet either, LOL.
They’re called communities on Lemmy, not subs. And if there isn’t one yet, feel free to make one! This platform is young still, and needs people to start filling the void.