Local regulations differ, depending on city, state, country. Typically if you are under 18, you will need to have your parents along.
No. Just have to be old enough!
In most states you must be 18 years old. Just ask the sales person.
No. It just takes money and usually 18 years old to purchase an air rifle. Air rifles are not regulated by the ATF.
buy one
If you look younger than 18 years old, then YES!
18 to buy a rifle or shotgun, 21 to buy a handgun or assault rifle.
18
18
At canadian tire
Have never heard of an underwater assault rifle. In the US, you must be 18 to buy a rifle, and 21 to buy a fully automatic rifle.
You need to state the model to even have a chance of identifying the age of the air rifle. There is no list of every air rifle by serial number.
18 in the US