Just some comments ....
Watering trees can cause them to develop a shallow root system.
Make sure the 'crown', the junction where the roots transition to the trunk, is set high enough. It should be at ground level of slightly above.
A biodegradable mulch around the tree (still don't cover the crown) will help with water conservation. I have thought, but not tried, cardboard or several layers of newspaper for this mulch.
I am a real fan of waiting until is is wet to plant 'saplings'. I place them in a hole, press the damp earth back around the bare roots and god decides if they survive.
This served me well until a couple of years ago when god took 7 of 10 trees in a drought. 2 were mature Pear trees and 2 were fig trees, my only fruit trees. (8m tall pear trees and 4 m tall fig trees).
Good luck ....
Ron