The first tree to survive long term in my care, was a favorite,
Punica granatum, or Pomegranate.
They are easy to work with, very resilient, and will come back even after being forgotten for a week without water. I kept one going for 38 years, from the time I was a junior in high school through college, surviving 2 times a year changes of apartments and living situations, through my nomadic years right after college. It survived dog attacks, children around the house and other disasters.
They have nice flowers and small leaves. Great tree for bonsai.