Literally saying; join to where you deserve, get out from where you shouldnt belong to. Shortly it says you must stay in your own place (since its not for you) see the first word from her answer "낄" 데 "끼"고 "빠"질 데 "빠"져라. This is excessive abbreviation.
You dont need to say KNOW but enough only with 낄끼빠빠 (embarrassed to mention this word coz its for young guys lol) and that situation is not that suitable for the example I think, you can say 주제를 알아(; know your self) for that case. I will give you another one; supposed that you guys are discussing about something and somebody who is totally ignorant bwt it try to join you even he is a layman tho. And now you can say it. 낄끼빠빠 ㅋㅋ