Would I be able to pair a first gen AirPods Pro AirPod with a second gen case and other AirPod

Hi AndrewRMa,

Thank you for participating in the Apple Support Communities. We understand you'd like to know if you can pair first generation AirPods Pro with a second generation case and AirPod. No this isn't possible. However, you can replace a case or AirPod if needed. This link explains more about this: AirPods Repair & Service - Apple Support.

We hope this helps.

Take care.