Yes pump as soon as they let you. My daughter was a preemie and didn't feed till she was 1.5 months.
So I stored a ton of milk. By then I only pumped since she didn't latch on. But I will tell you this. Don't get discouraged. Continue on a schedule. I was considered "the Cow" of the nicu since I pumped soooo much milk. I was pumping more than 12 ounces.
Just eat healthy and TONS of water.
My colostrum was pumped just fine. But I had no choice. I couldn't nurse cuz he was on a ventilator for his first 2 days of life. You won't get much, but then again baby doesn't need much the first couple days. I got probably 3 Tsps every pump session which the lactation.consultant said was enough to fill his belly for the first few days. I was consistent though and that matters. I do hear babies are much more effective at getting out the milk than the pump though!
The lactation specialist at my hospital said it would take a couple days for milk to come in, first it's colostrum and you can't pump that effectively. So, usually, you can't pump immediately after and get any real results. Your supply will typically start out very low and slow. But everyone is different so you'll just have to see.
Also what I found helpful was a Bobby pillow so I could feed him while pumping, a double electric good quality pump and a pumping hands free bustier. It holds the pumper for you do you have your hands free to feed baby and it outs a little pressure in your breasts and I got more milk that way.
Yep. You'll want to pump frequently. Every two hours like clockwork even through the night for awhile. Then once your supply is steady and she is a bit older then you can stop pumping through the night but you'll want to keep up the every two hours thing for awhile. I would drop it to 3 hours and if it drastically affected my supply I went back to 2 hrs. By the time he was 9 months I was pumping every 4 and had a ton saved in the freezer. My son was preemie so I pumped right from the moment he was born. They let me put him to Breast a couple times but that was until he was a couple weeks old so I had been pumping my milk for him til then. He never latched after the one time so I exclusively pumped for a year.