As you have sandy soil, you should have some very very happy sweet potatoes.
I used to grow old time veiny white sweet potato, that were very ugly, but so delicious that I lost interest in the red ones. Rarely I see white sweet potatoes in the grocery store - and they are usually extremely expensive.
I grabbed slips from the neighbor. She’s had some growing volunteer for 20 years that I know of.
/johnny
I don’t think I’ve ever seen a white sweet potato.