Grafted trees will fruit within 2 years as a norm, this goes for dwarfs and full sized trees purchased from a nursery since they usually don't
sell trees that are not at least 7 years old for the standard trees.
If you grow a fruit tree from seed it will be 7 years before you
should expect any fruit and usually at year 8 they start producing more fruit each year.
All fruit trees will go through a fruit drop unless all conditions are perfect for the tree to be able to set and ripen all the fruit.