When to Get Travel Insurance?

[MamaBear58]

I haven't done this is a while, and never for domestic trip, so educate me. Do I get it once I reserve the room-only? Or do I wait until the other components are added--tickets, flights, possible rental car? They are really the non-refundable items, and that's what I insure, correct? On the other hand, doesn't Allianz require that you buy within 14 days to include kids for free? Within 14 days of what?

Have no plans to cancel but DH's mother is elderly so in the event of the inevitable, or something beyond our control (like weather or terrorism), I want coverage. We don't need the medical coverage.

Thanks in advance!