Deciding to carry a firearm for personal protection comes with many responsibilities. The first thing that needs to happen is you need to become very familiar with the weapon you chose. Many factors go into to deciding the firearm you wish to carry. This post is assuming you have already decided on the firearm.
If you go out and purchase a weapon and carry it with no experience you are asking for trouble. You need to train your self to be able to check to see if the gun is loaded. You need to train yourself on how to load the gun. You then need to train by shooting target ammo at targets. You need to train yourself to always look beyond what you are shooting at. Make sure you can hit the target you are shooting at.
One you are proficient with safety, loading and target shooting you need to purchase defensive ammo. It is a little more expensive than target ammo but you need to make sure you can hit with it and your gun will function shooting it. You may need to try a few different brands too figure out which functions the best for you.
You also need to make sure you are mentally prepared to take a life. If your intention is to scare someone buy a halloween mask. If you are not prepared to take a life any hesitation could cost you or a loved one's life.