In order to establish an online classroom you need rules (or at least one rule). "No hats." and "No gum." do not seem to fit online, so let's go for "Respect." The rule: Students and teachers will show respect to all past, current, and future class members. Yes, there are elements of being reactive as well as proactive with our respect. Think before you post, please.
Next, how will you build relationships within the classroom? How will students and teachers introduce themselves and get to know each other? We teach children, "Stranger danger." How do we undo this in an online classroom? Note: Danger in an online classroom refers more to "cognitive risks" than to "personal safety risks." The relationship builder: Introduce yourself, tell us where you are from, what you do, and what flavor of Kool Aid you are most like?
Finally, yes finally, create interesting and relevant learning activities which lead to the students creating positive learning memories. Offer students the opportunity to work alone and to work together. Expect and accept their best work and provide quality, timely feedback. And, as a teacher, enjoy the journey!