My first two peach trees were volunteers growing along the path, where they didn't get enough sun. This is West Virginia, zone 6, on the ridge. One of those small trees produced one fruit one year, a big lovely peach, ripe on the last day of June. My neighbor had several mature peach trees, but two of them produce peaches every year--one year it got down to 12 degrees F while blooming, and the tree still made peaches. But these two trees get brown rot every year, ruining the fruit a week before it's ripe. I've been campaigning to cut them down and burn the wood, so they don't affect others.
Meanwhile, I planted a PF 19-007 in my orchard and moved that little tree that made the super early peach into the orchard where it would get more sun. I consider the earliness a bulwark against brown rot, since hopefully the fruit will be gone by the time any spores arrive. I'm about to plant a third peach, a PF 8 Ball. Here I should explain that PF is for Paul Friday, the developer of this line of peaches, which he calls Flamin' Fury. I think that sounds like a wrestler's name, and PF 19-007 sounds like a robot, so I have suggested Perfect Peach or Voluptuous. Two years later I got my first load of peaches from that tree, and the transplanted one made three (this was last year). My criteria are earliness, brown rot resistance (so far I haven't seen much bug damage) and ideally a large, reddish, freestone peach.
But I also learned some lessons from a peach I transplanted in after it volunteered in my neighbor's garden. It was so vigorous I needed a wheelbarrow to bring it home the same fall--itt was already five feet tall. Within a couple years it was 12 feet tall and loaded with pink flowers. But it produces few fruits, and inferior ones. I just cut it down. It also had a big canker on the trunk, I believe as a result of southwest disease--where black fruit tree bark warms up in the winter sun, on the sunny side, then freezes hard at night, causing cracks that can be invaded by rot organisms. So this cold winter I wrapped rags around the trunks of my other two peach trees to protect from the sun. And I'm thinking I should buy some tobacco to sprinkle around the bases of my fruit trees, as I read that will repel or kill the peach tree borer. But I've also learned to keep things away from the bases of all my fruit trees, so I can see if there is evidence of borers (and to keep winter mice from finding a cozy spot to chew on bark).
It's said that peaches reproduce more true than other fruits, so planting a peach pit is more worthwhile than an apple or pear seed--which will result, years later, in probably inferior apples or pears. But I consider it worthwhile to get already grafted, named varieties likely to produce desired results.
Also note that you need to consider pollination requirements for most fruits, but you can do fine with one peach tree, if that's all you have room for. So I read. Also, they tolerate black walnuts lurking nearby, which apples won't, and pears maybe.
Couple more things--peaches (and most other tree fruits) really need thinning to produce good, full size fruit. I picked 250 little fruits off my Perfect peach last year, and still had 50. And last year I tried using fruit bags to protect my apples, pears and peaches from squirrels and bug damage. These are green nylon net bags with drawstrings which make it easy to put them around fruits. One year is not enough to tell, especially since last year was anomalous--extended drought, so that the bees, wasps and hornets let me know the pears were THEIRS in the heart of the harvest season--but if I get a good fruit set again this spring I'm gonna order another 200 bags. There are several suppliers.