.......I'm not even sure what to say....
Please don't hit your puppy with your open hand
.....may I suggest maybe shaking a can with rocks/pennies in it so the loud noise will scare him/her along with a very loud NO! This would have to be done at the moment he is doing something wrong...not a second later or he won't understand what he has done wrong.
Also, if you feel overwhelmed raising/training a puppy, may I suggest rehoming? Training a puppy may not be for everyone.....