Congrats on your new Airstream!
If you’ve been reading this forum, you know it’s a fantastic resource. Virtually every and any issue has been experienced by someone else, and they’re happy to offer guidance here, mainly without snark.
As an experienced RVer, you know the value of a robust tool kit and accessible repair supplies. That said, we found ourselves in need of quick emergency repairs for two separate water leaks for our new 2019 27 FC FBT that appeared after a day of heavy rain. Both leaks involved poor caulking applied around exterior window frames. So, my recommendation is to have a tube of Sikaflex or clear silicone handy for your first real world “soak test.”
Current: 2021 Classic 30' RBT
Past: 2019 Flying Cloud 27' FBT