I guess you should know who you want to talk to, then have some other medium of contacting them, and then when you decide to move your conversations into a secure medium you meet or video call and pass the simplex key? That sounds about right. I suppose with the levels of privacy it espouses, there really can’t be a form of “online communities” because people wouldn’t want to reveal anything about them without already knowing the person they are revealing details to, and vice versa.