I live in Utah zone 6/7 and grow around 33 varieties of berries, fruits and nuts in my .25 acre urban, food forest. Here's the links to keeping your fruit trees small:
Dave Wilson Nursery Backyard Orchard Culture
https://www.davewilson.com/home-garden/backyard-orchard-culture/
"Grow a Little Fruit Tree" by Ann Ralph
https://a.co/d/6T1Yfa2