I read on a website that sells airsoft guns “You must be 18 years old to purchase this product. The sale or shipment of this product to residents of California, Connecticut, District of Columbia, Delaware, Illinois, Michigan, Massachusetts, New Jersey, New York, North Carolina, Puerto Rico and Canada is prohibited. Check your local laws before ordering this product. We recommend the use of protective eyewear whenever using or near the use of this item. If this is true how could I obtain an airsoft gun?

I have two dogs and they are less then 10 lbs each. I want to bring them to the beaches this summer, but I don’t know what beaches I can bring them too. I live in Boston, Massachusetts and with summer approaching rapidly, I’m in a knot! Thanks for your help!