Public meetings, religious, political, or otherwise, including picnics, parties, and entertainment for charitable or religious purposes, may be held in any public park upon first obtaining permission from the City Administrator. Such assemblages shall be conducted in a lawful and orderly manner, shall be under the supervision of the City, and shall occupy such ground as may be reserved for them. Permits shall be obtained from the City Administrator for use of parks and facilities by organized groups for all such purposes including athletic and sporting activities.