>>2698158Vast majority of apple trees will be already grafted, they should know what kind of rootstock it's grafted on, how vigorously tree will grow and height it'll reach will depend on rootstock type so it's kind of important.
When you put it into soil make sure you plant it around root crown height, not graft union height or even deeper.
Also when looking for specific cultivars make sure whatever you are choosing is at least somewhat disease and pest resistant, some cultivars don't work well without constant spraying like they do it in orchards.
