can someone explained the self employed feature?

I do want to see how the entertainer career meshes with Get Famous, as well as using the ability to sing with guitar and piano (the family just got a karaoke machine so he can start on his singing skill while still a child) when he's performing. Since I play on Long lifespan he'll probably get to the top of the Entertainer career while a YA, then as an Adult I can have him do music producing.