Practice, practice and more practice with your weapon of choice......you owe it to the animals you kill to make a quick clean kill.......they eat much better when you can do this as well......
Practice until your shoulder hurts, then practice some more.
When standing broadside, the top of the rear shoulder offers the greatest margin for error as an aim point. If the animal is not standing completely broadside to you, choose an aim point where the trajectory of the bullet will still pass through the heart and lung area. Shots from direct rear and front are to be avoided until the animal presents a more ethical shot.
It's not at all uncommon for deer to run some distance after being hit solid with a bullet. Pay close attention to where the deer runs so that you notice specific bushes or trees that it ran past during its exit. A thirty-minute wait before beginning your search is not too long. Some folks wait much longer. Once you start searching for the animal, if your unsuccessful search doesn't last for at least an hour, you haven't searched at all. And be sure to carry a good flashlight on evening hunts so you can search in the dark.
Find a video or two on YouTube on how to clean a deer. It's not so much that you need to clean one yourself, but demonstrating to others you've put forth the effort to learn what's most important about the sport, to provide meat for the dinner table.
There are no stupid questions when it comes to being a newcomer to the sport. If you have any doubts whatsoever, ask someone.