2003 Nissan Sunny Problems

Dear All, I have purchased a second hand car and did not get the car manual. My engine light on the dashboard often lights up while i'm driving and this happens when gear change from 1st to 2nd. I think there must be a problem some...

The car has problems starting in the mornings and goes off upon take off. At times it goes off in the evenings too when i am leaving the office.