Congratulations, I suppose, on your new position.
As someone who didn't have the option of working at Starbucks for his first job (They weren't east coast at that time), let me offer you some friendly advice that you won't understand for far too long.
Quit now before you start.
Leach off your parents for several more years.
Trust me, you have many more years ahead of you for work. Why work now while you're young? Go out and have a good time.
"We couldn’t do diddley poo offensively, we couldn’t make a first down, we couldn’t run the ball, we didn’t try to run the ball, we couldn’t complete a pass - we sucked." ~ James Ernest Mora