Home vegetable and fruit gardening have become much more than an outdoor activity that is "trending", but a very strong "movement" these days. Planning for a home orchard will take a bit more planning than we typically do for the annual vegetable garden. Fruit trees are more of a long term investment in the home landscape.
There will be several parts about planning for a home orchard that will need some thought even though it may be lots of fun just to jump in and start planting. The space allotted for the orchard will shape not only how many trees you can plant and manage but the sizes of the varieties you want to grow. The smaller the mature size, the more fruit trees you can plant in a given space. It becomes the preverbal "Chicken or Egg " story. Unless you have unlimited space, consider the varieties of fruit trees that are available in dwarf or spur types. The goal would be to have a mature fruit tree that is producing fruits that remains in the six to eight foot range when mature. Some varieties are naturally larger than others, even when produced as a dwarf or spur type tree. Standard fruit trees can mature at the thirty foot range, while the smallest double dwarf of the same variety will be that six foot size. Even if space is not a concern, it will take a lot more time and resources to manage large fruit trees.
Once the varieties are chosen and you have determined how many fruit trees you can have in that space, another consideration is that of pollination. Some fruit trees will need to be cross-pollenated, also known as self-unfruitful, which means an additional tree in the orchard. Most apples are that way, but not all. The stone fruits like peaches, Sour Cherries and Nectarines are self-fruitful meaning you only need one of them and you will get fruit. There is also a category called partially self-fruitful fruit trees. Partially self-fruitful trees will produce a larger crop if cross pollenated, but have the ability to produce a partial crop if that does not occur. All the fruit tree catalogs and any on-line store will provide you that information. Ask the right questions at the garden centers to be sure before you purchase your fruit trees. There will always be exceptions to the rule. Examples include the sweet cherry variety called Stella which is self-fruitful with other varieties requires cross pollination. Rome and Golden Delicious Apples are partially self- fruitful and some apples even have sterile pollen. They can produce fruit, but cannot be a pollinator for another variety.
Proper spacing ensures that as the fruit trees mature, annual pruning and any pest management program for insects and diseases can be more easily done. Proper spacing also means that the home orchard will receive plenty of light and good air movement, for promoting better growth and development of the fruit trees and any fruits produced.