Depending on conditions, variety and rootstock (the plant to which the fruiting variety is grafted) many fruit trees will begin bearing in their second or third year. Some trees will even set a few fruit in their first year, but growers typically choose to remove those, allowing all energy to go into developing tree size and structure. Some varieties of apple, pear and cherry on standard rootstocks can take five years to begin bearing.
With weaker-rooted, slower-to-establish and/or very precocious trees (e.g. trees on some dwarfing rootstocks) especially, many growers remove all fruit for the first two or three years: the development of tree size and strength is given top priority.
In any case, if you choose your trees wisely and give them the basic care they need, the wait is sure to be worth it. And think of the wonderful time you will have looking forward to the fruit!