probably not
Not if you follow the laws.
Your local police can give you the current information.
Since you posted the question on the internet, do an internet search on Maryland gun laws.
Yes, if you follow the laws
It's up to your parents and the laws of the country where you live.
If it was illegal to discharge a BB gun then they wouldn't make BB guns. So the question is, Where is it legal to discharge a BB gun? Every state, city or country has different laws about BB guns so it is best to check with local law enforcement or city ordnance's to find out about where you want to shoot.
http://www.nraila.org/statelawpdfs/MDSL.pdf
It depends on your local laws.
Depends on the parents and local laws (if any).
There are laws that restrict sale and use of a BB gun to anyone under the age of 18, and specific laws prohibiting use by anyone under 16.Felons may own a BB gun but not one that can also fire pellets.There is also an issue with regards to what qualifies as a BB. Which may mean that even AirSoft BB guns are not allowed.
It depends where you live, and what the laws are for using BB guns on small animals. Usually it's not unlawful to use a BB gun on small animals like rabbits, squirrels, pigeons, etc.