Pairing two different airpods

Yes. Assuming they are the same AirPod model and generation. You can link and pair them by placing them in a compatible charging case, and following the steps in the support document linked below.

click here ➜ Set up your replacement AirPods or charging case - Apple Support

Yes, you can.

Use AirPods with iPad - Apple Support

Note that, though you can pair both, you can only connect to one set at a time.