..hmm..slang or something ?

 Not everything has to be slang

It means to get involved  or meddle with or chime in or stick your oar in/ poke your nose into

So basically he meant don´t get involved in everything

So isnt this called slang ?

well none of the things I wrote in English is slang.  So why must they be in turkish .

None of the things you´ve written in English is slang. However, "bir þeyE maydanoz olmak" is usually used in informal Turkish.

Or

bir þeye burnunu sokmak

I heard much..but never  "bir þeyE maydanoz olmak"..and i heard much...

 Ãžimdi gördüm, teþekkür ederim.

nemli deyil aabi.

ReyhanL there is your slang

thanks so much for the translation ....hope one day i can be as good as this ...lol ....

Being a little picky here but you should say either:

Nothing you´ve written in English is slang   or

None of the things you´ve written in English are slang.