Very few people have the legal right to discharge a firearm on their property. The enforcement side is spotty at best, but that's not what is discussed here. If you think that being able to fire a real gun means you can shoot a replica anywhere, you are wrong.
Wether it's enforced by the police is another question, but that does not change the laws.
When you talk about airsoft, forget anything else exists. To be TOTALLY legal, the user MUST be 18, and the place where the guns are used MUST be approved and insured for that use.
Many folks refuse to wait until they are 18, and just play anywhere they want. Did you check the threads about idiots being caught with airsoft lately? Go read that.