HOW DO I TRAIN THIS DOVE? I DONT KNOW HOW TO BOND WITH IT. PLZ ANSWER ASAP?

i just got a diamond dove from petsmart. i know, its not wise to buy from there, but i am a bird watcher, and the bird has VERY healthy and normal behaivior. he will fly out of the cage if the door is open, but is natrually terrified of me. does anyone have some advice of helping this bird not be afriad of my hand, my presence, voice and movement. my other conserns are that when i change the birds food and water in the cage, it is scared of my hand when i put it in the cage to take care of the ffod. i feel i may be making things worse. help please?