Put shotgun shells in it. And for your situation, please keep the safety on while you do it. Don't point it at anyone. Tell your wife and kids to go in the other room. Better yet, tell them to go to your wife's mother's house. They don't need to be around while you experiment with your new Man Toy. Then, join the military. They are relatively good at training idiots to load firearms. This will be benificial to you. It may even prevent you from splattering the interior contents of your skull all over the walls of your home and save your wife and kids from experiencing an extraordinary amount of psychological damage. If you seriously need to post this type of question on the internet, then it is probably not a good idea for you to own a shotgun. Please be careful, sir.
Depending on the load 20-100 yards.
Depends on what gauge, what load and barrel length
I'll take it for free :)
It depends on the load and other factors but a good measure is: 12 Gauge 28" barrel=151.50dB
Depends on the load, angle of fire, terrain, weather, etc.. a couple of hundred yards at least.
It depends on the gauge, load and quantity. Prices can range from .10 to 1.00 USD
Depends on the gauge, load and power level. At least a few hundred yards.
30-300 yards depending on load, angle of fire, etc..
Depending on barrel length, load and choke, anywhere from 10-100 or more yards
Depends on the BA, distance, type of buckshot, load velocity.
No one answer, since there are several different types of 12 g shotgun, and they operate differently.
You need the services of a gunsmith