Welcome! You might be interested in the welcome thread, first of all.

If you're interested in volunteering to speak about rationality topics, there may be easier ways to try it out than starting and advertising a new organization. (Plenty of smaller humanist/philosophy/discussion groups are happy when someone volunteers to present.)

Also, since you have a new account, can I ask whether you've picked up Less Wrong-style rationality fairly recently? It's worth noting that the earliest burst of enthusiasm isn't as reliable as it seems, and one should often scale down one's initial ambition accordingly. There's always opportunity to add more responsibilities later if it goes well. (This Kaj Sotala post touches on that phenomenon.)