Complex sentence: It is a crime to fire or brandish airsoft guns in public view; airsoft guns should be fired indoors on private property or anywhere designated for use of airsoft gund such as an outdoor or indoor airsoft field.
Split into simpler sentences: It is a crime to fire or brandish airsoft guns in public view. Airsoft guns should be fired indoors on private property or anywhere designated on an (outdoor or indoor) airsoft field.