The first step is calm communication. Most of us (I know not all of us) have done this before. Our major goal is to keep communicating, keep connecting, and keep teaching.
It is easy to get overwhelmed. Here is a one-stop resources. Also please reach out to Kate to talk about modifications to your class. Everyone's course is so different, it is actually much easier to work individually with faculty on pivot plans.
I'm sure it doesn't surprise anyone that Harvard's Academic Teaching and Learning Centers are the Gold Standard for Faculty Development. They have put together an incredible resource for their instructors on Best Practices: Online Pedagogy. Be forewarned. We can't do everything from an IT side that they are doing at Harvard, but you'll find that your basic questions can be answered here. If there is anything you'd like to know more about, please email Kate.