Yes you'll start off as a barback and he'll teach you the trick of his trade.
The thing with bartending - it's an important position in a nightclub of which referrals are prized in order to get a job in a reputable establishment.
In my former nightclub, I hired 2 bartenders with 2 barbacks to cater to the crowds. It's when 1 bartender goes on leave (sick/awol/annual leave) that the apprentice gets his shot to shine.
Bartending skills is not the only criteria in keeping a bartender around, it's also his youth, attractiveness and ability to freely mingle/interact with patrons that comes to the bar.
A good bartender earns good tips.