No "back to school list" per se. But you can check the local back-to-school lists and have a pretty good idea what to get, if you don't have items --- crayons, markers, colored pencils, construction paper, posterboard, pencil, pencil-sharpener, erasers, stapler, paper clips (basically home supplies)....
Those who have yet to be contacted by teachers, it's possible they haven't assigned teachers to you yet. This can happen when they have more students enrolling than they expected.
Even for those whose books haven't arrived yet, on the start date for school (or prior?) the "Introduction to On-Line Learning" lessons should be up. Those are for YOU to review. And you should be able to do those without your school curriculum (or at least, that's what they've been like in the past) - they'll give you a virtual tour of how to do attendance, etc. etc. via that lesson. So you can at least get THOSE out of the way.
Your teacher, once you have one, should be able to give you direction about how the delayed start will impact your school year. We got our supplies two weeks late the first year we registered; they simply told us that we had an extra two weeks to finish up in the spring, after school was supposed to be over. That was the first year that our state had a state-wide virtual school, so most of us were in that (late curriculum) category. They also encouraged us to catch up as much as we could in the interim, but we did have that cushion at the end. My daughter ended up finished early despite our late start.
You may be able to do some school without your curriculum - if you have art supplies on hand, you might be able to find some art lessons that you could do, since those lessons are mostly on-line (no text book), for instance. For K, something that you'll learn later in the year will be full name/address/phone number -- so you could work on that now, if you haven't already, and that way it'll be out of the way when you do encounter that later in the year? Otherwise, if you go to a museum, zoo, or etc. during this time that you don't have your curriculum, you can enter the hours you spent doing that under "science" or "history," etc.
Hope that helps! We start tomorrow .... I still need to clean off the desk tonight!