I am a student pilot so please be patient with me.

Let's say I was told to contact NorCal Departure on xxx.yy frequency.
I transmit :" N33A, xxx.yy, good day"
I switch to a new frequency and say:" NorCal Departure, Warrior 4333A"
Controller responds:" Warrior 33A, climb and maintain 5000'"
Now the question, when I read back " climb and maintain 5000'" to the controller, do I start the transmission with " NorCal Departure" or just read back :" climb and maintain 5000', Warrior 33A"?
Thank you.