Um, a tailslide is a skateboard move where you slide on the back of your board. The only way you could do it on a scooter is if you somehow had something behind your back wheel to slide on. A lipslide is a grind you rotate 90 to get into. You slide on the deck as it moves.
lipslides on q/p's are fun. in the beginning it feels wierd but eventually youll probably just do them without noticing.
anyway, i ride reg. and do an oppo 180, when you get on the coping make sure your wheels dont touch top/bottom of q/p then lean forward and keep practicing. just get the feels of it and your fine