There is no licence requirement to own/possess a BB gun in the U.K.
There are, however age limitations set by law, and stringent regulations concerning use. When purchasing a BB gun ensure the supplier provides you with details of these laws/regulations. Leaflets/Information booklets concerning these matters are also available from local Police Stations.
Minimum age to purchase a BB gun is 17 years. An adult must supervise persons 14 to 17 years of age. No gun should be carried in a public place unless in transit when it should be not be loaded and placed in a carrier type bag. Note, guns must not be concealed on ones person.
The age restriction is 18 years of age to purchase and use. If the user is under age there must be parental supervision of the firing.
yes
I do not know where Derbyshire is but from the name I guess it is in the UK. See the link Below for UK Airgun laws
No.
Yes you do.
yes
probaly
Australia requires you to have a category "A" firearm license to own a BB gun
see the link below for the air gun law in the UK
Yes
It all depends on the country where you live.
no you dont
License is the correct term. Whether you need one depends on the local, state and federal laws or country where you live
YES! or you could harm something or someone