How to start exclusive pumping after birth?

I am due to have my c-section in 12 days. I was going to breastfeed and pump but now I am only wanting to pump. How do I start exclusive pumping after I have my baby? I know your milk doesn’t come in until 5 days pp. also my doctor won’t give me a prescription for a breast pump. I have Momcozy s12pro can I use those or do I need a bigger one that you plug into the wall?