Can someone explain pumping to me???

M

Like when should I pump? For how long? How many times a day. I am only 5 days post partum so my milk came in 2 days ago. I pumped a little from each breast just to figure out how to use my breast pump properly. If I pump and then need to feed shortly after will there be enough milk?? FTM no idea how this works??? Any help is appreciated.