Burglars come into your outbuildings or home in order to steal your possessions. They by definition want nothing to do with you, just your stuff. Many burglars will knock on your door hoping no one will answer. They then feel safe breaking into your empty home. You should always see who is knocking on your door but not by opening it. I look out the side window behind them to identify them (try not to look out the peephole.) I have even frightened some by talking to them through the closed window. I tell them nicely I’m not interested and to leave. I’ve never had any person not leave my property when asked. This is normal even for a bad guy. In my opinion the more a person doesn’t comply with you, the homeowner, the more likely you need to call 911 and wait for the police while armed.
The typical burglar, not getting an answer at the door will pick an entry point and force it open. It could be kicking your door in or prying open/breaking a window. If you didn’t answer the door the burglar might not know you are home. The vast majority of burglars will leave when confronted verbally. Set yourself up in a position of advantage to engage the bad guy, identify yourself as a homeowner and wait. Remember no matter what your local and state laws are I’m sure you don’t want to shoot your family member coming home at an odd hour or something similar. You must ID the bad guy as a bad guy. You should be training to understand your local and state laws and receive some training from a competent instructor as to the real world application of those laws. You need to be crystal clear on when you can legally shoot someone. Then you need to be crystal clear when you WILL shoot someone in your home and under what circumstances. Just because you can legally shoot someone doesn’t mean you always will. Sometimes it will mean you definitely shoot them.
Sometimes home invasions start exactly like the burglary except they knock hoping you open the door. Then they can push their way inside. If you don’t have an alternate way of viewing the person at your door, I suggest standing back and talking to them loudly through the closed and locked door. Having your eye to the peephole when it is kicked in is no way to start a gunfight. If they know you are home and force their way in then you have a robbery/home invasion and not a burglary.
A home invasion robber is a person who doesn’t care if you are home and will use force against you. In Arizona there is a presumption that a person entering your home against your will is on its face a lethal threat whether they are armed or not. Other states do not allow for this. You need to know how your state deals with this. If you have the option of taking an eight hour class over a four hour beginning gun class you should find one that uses much of that time educating you on shoot or don’t shoot. If it covers this topic in depth then spend the money on the longer class. This is more important than becoming the greatest shooter in the world. Don’t worry you can still become a great shot. It just takes commitment and time.