First off, don't get stressed about it. As long as your baby is fed, that's fine.
The first thing you should do after the birth is skin to skin - put your baby on your chest with both of you wearing nothing at all between you (a nappy on your baby and a dressing gown over both of you is fine!) offer the breast as soon as possible after birth - nipple to nose and tummy to mummy.
Make sure the midwives are fully aware that you want to breastfeed and that you're worried. Ask to see the breastfeeding or lactation consultant as soon as possible.
It is likely to hurt to begin with but only for the first little while of each feed. Count to 10 slowly and you should find that the pain recedes. Wallow in Lansinoh, well worth the money, before and after feeds. A small blob on your finger and rub into and around your nipples.
I had to give a few formula top ups to start with as ds was dozy from pethidine. I was given a syringe to dropper it in with because of the possibility of nipple confusion between breast and bottle. I was also shown how to hand express so that I/dp could give that.
Bear in mind that, after the first few weeks and barring any other problems, breastfeeding is significantly easier than bottle feeding - just whip a boob out and go, no sterilising, mixing, measuring etc. www.kellymom.com has a lot of very good information on all aspects of breastfeeding including mixed feeding so have a read through all the information.
It might also be worth finding your nearest breastfeeding support group and going along before you give birth. It's offered as part of the antenatal classes in my area, and a really good source of real life support. Ask your midwife, but a lot of children's centres host them. You could also check out La Leche League and breastfeeding network for information.