I’d choose site carefully, if you have options. When I moved into our house, there was a vegetable garden near a small
pond. I started
gardening, added beds, planted a few fruit trees, added a
fence. The problem is that it is in a lower area and gets some shade from larger trees near pond (west of garden). Not a problem for berries and veggies, but it has caused problems for fruit trees with late frosts and maybe damper soils. I’ve planted additional trees in an area uphill about 50’ that gets full sun and the difference is noticeable (I’ve got some overlapping varieties and the “upstairs” ones are doing better). I didn’t think hard
enough about siting those first trees, and as a result, I’ve eaten less fruit (particularly peaches). Fruit trees teach you observation and patience.
I’d also have talked to more people about sourcing trees, varieties, pruning, rootstocks and grafting. I started out with a few larger (and expensive) trees from nurseries. They were a good start, and are doing fine, but I kinda just let them go and was reluctant to prune heavily. Now I’ve learned to buy bare
root trees, and learned much more about pruning (how, when, why). I didn’t believe small trees would catch up with larger trees, but they have. And I’ve learned to take those big cuts on a peach tree to train to an open center. I think fruit trees are kinda like dogs… I prefer to get them young and train them myself.
Another thing is to know who you are growing for… we have nearby family and like to eat fruit and make some cider. I like to bake a few pies. But when I buy apples, for instance, I don’t buy bushels. And yet, in a good year with bigger trees, this may be what you get. So I’ve gone with techniques to keep trees smaller and grafting multiple varieties on them. Ann Ralph’s book Growing Small Fruit trees is a good start, but you will likely need to modify for your zone/climate/soil.
Good luck- it’s a lot of fun to have a small orchard.