Q.Cherry tree with no fruit
I have 2 cherry trees about 10 feet apart. They were both planted about three years ago. Today one tree has cherries, the other has none. Why?

Are you growing Sour or Sweet Cherry Trees?
Sour Cherry Tree's mature and began to produce fruit around 3 to 5 years of age. A Sweet Cherry take a bit longer at 4 to 7 years.
Here are some articles with more information.
https://www.gardeningknowhow.com/edible/fruits/cherry/cherry-tree-not-fruiting.htm
https://www.gardeningknowhow.com/edible/fruits/cherry/pollinating-a-cherry-tree.htm