I would start off saying, "Hey everyone! How is everybody doing?" Some might respond, some might not. You all correct; maybe some of them are afk, not allowed to talk or are busy doing things that they don't have time/want to talk. So I might ask again,"Is anybody doing anything interesting?" or "I'm sailing right now if anybody would like to come." Or, "Oh, I just got such and such from Tormenta ... or Dark hart ..."
Now it doesn't really bother me a lot of times that ppl don't talk in the guild, as long as they don't do that all the time. I could enjoy my quiet time a lot. But if they stay quiet all the time, and after we try to start conversations several times nobody responds, it's up to you. I haven't left a guild because ppl are quiet, but I might, if I find other guild that is really interesting. So, you'll know when it's time for you to move on.