Are SLANGS useful for english learners?

i saw a lot of slangs being used by native enlish speakers.I think it is important to understand them when spoken . And i am trying to make use of these slangs to get myself into the real english...

Have you seen panda yet

do you often go to the zoos and forests to enjoy animal company?what animal do you often enjoy most?do you like panda and what do you know about the canda?

are you useing make-up

There are kinds makeup that people use to dress up a bit.Are you one of them who appear attractive in the public with makeup?

"bodywash" OR "toilet soap"

which do you like to use between bodywash and toilet soap? Which are most people useing more often?why do they like it?

what is it like when yu first heard your first baby came to birth?

Is the feeling a sensitive, subtle and strange one as everyone says?cant it be a cry?Does everything change for a family ever since this small kid 's arrival .The world is more clear,isnt it?