Welcome to the forum! Which course(s) do you teach? There are specific boards for each course that will be able to offer you more help. There’s not a dedicated phone number to call, but there are several support articles on support.code.org that should help you get started.
For example, this support article walks you through how to chance the lock settings on tests in the Computer Science Principles high school course.
If you’d like, you may also look here to find a local Regional Partner who will be able to provide info on training for these courses.
Hope that helps!