I Have a question about the Sims game Bustin' out, If you've finished the game please help me?

I have decided to be in the movie star business and I just got to Malcolm's house and one of the goals is "Finish all 7 careers to see your dreams come true" How can I do this. If I want to do another job say fashion then I need to quit my movie star job and start at the bottom don't I?