Being a street skater? is it illegal and are cops effing PRICKS??!?

well i wanted to skate in the street (well u kno what i mean by street like crossing the street and these cops were just like friggin EYEING me like coyotes looking at a dying bull and i wanted to skate in a parking lot but my mom said no (for obvious reasons liek me trying to do an ollie falling breakin my arm and givin em a lawsuit out the ) could i like ask the manager to skate in the lot after hours and sign a paper saying i am held completly liable for any accidents occuring and like can i skate in the street legally or can a cop pull me over for it and gimme a ticket or can i say like "up your's beeyatch dont be a deek, cuz its legal here k? so dont me pullin me down"? or can they really give me a ticket? i understand that skateboarders have a bad rep for destroying public AND private property BUT if im not grinding or jumping really big gaps and SMASHING my board against the concrete its ok right? as long as no skateboarding sign isnt present right? ty