I have grown both Apple and Peach trees. They were bought from a nursery and started in pots.
Here are some tips when planting from the pot.Cut the roots about an inch deep along the edges. This help the root regrow outside of the confined container they have been growing in. You do not need to over cut. Dig a hole about two feet wide and as deep as the pot.
Fill in the edges with soil that is a mix of 1/3 compost 1/3 soil and 1/3 perlite. Cover the bottom and sides with two cups of root treatment. Cover with mulch 2 to 3 inches deep about 4 to 5 feet around the tree. To not crowd just around the trunk.
Water two to five gallons a week. Make sure the water soaks in deep to promote deep root growth.
In the early fall to late spring you will want to cover around the base of the tree, or rabbits will eat the bark during cold weather. I have lost several trees to rabbits. Once the bark is removed the tree becomes susceptible to disease. I use either cardboard wrapping paper or a plastic drainage pipe.
Also for the first couple of years you may want to support the tree against heavy winds. I would use stakes and ground the tree in at least three directions.