Q.Lower leaves turning yellow on recently planted papaya tree
Papaya tree from Lowes, approximately 6 ft tall, recently planted in full sun. We have had lots of rain past 2 weeks. We live in eastern NC.

Yellowing leaves most likely indicate some stress in being moved and planting.
To much water can certainly be the cause also for yellowing leaves.
Daily water for the first 2 weeks and proper care is listed in the link below.
https://www.gardeningknowhow.com/edible/fruits/papaya/growing-papaya-fruit.htm