How do drug dealers (bznaza) become bznaza in the first place?

Weird question,i know,but last night i was thinking and pondering,until an unordinary question popped up in my brain.How do bznaza become bznaza?Do they just get drugs from somewhere and deal them or am i just oblivious to the whole progress of becoming one,i would appreciate an answer to remove this itch from my brain(am only 14 think of it as helping a child), Have a blessed day or night!