David and Gecko! He/she is a beautiful bird!! Wow - pretty good that he/she will eat from a bowl that you are holding already! Notice if you can what he goes for first in the food bowl... those will be his favourites that you can use later for training. What are you feeding him/her? Does he like vegetables and fruit... maybe carrot, broccoli, peas, blueberries, apple, pomegranate, etc? Try millet spray too - a favourite of a lot of birds. Are you feeding a seed mix? Which seeds is he picking out first? When you have discovered his favourite food, you can try offering them from your hand... or dropping them into the bowl he's already eating from.
Just take it slowly. You want to associate yourself and your family with wonderful experiences for him... and favourite foods is the way to go with an untame bird.