Make sure the pinkie you are offering dead or live is warm. You can achieve this by placing the pinkie on something warm like a heat mat.
Snakes especially hatchlings locate their food using heat emitted from their prey, i.e. if the pinkie is cold he will not recognise it.
As they grow older, smell will play a bigger role and start excepting even less warm and coldish food.
Make sure the hatchling has a good hiding place, since a stressed out snake will not eat.
When you attempt feeding him, warm up the pinkie and place it near your snake, and leave him alone in a quite place, dont try to force him or hit him with the pinkie, he will just move away.
You will have time to do so when he is older dont worry :)
Hope this helped. If you have any other questions dont hesitate to ask.
P.s. If the snake is less than a week old and hasn't gone through its first shed, it will not accept food. Snake hatchlings do not eat until they shed for the first time. In the mean time they use up the yolk form their egg which acts as a kick start for their early life.