Expect it to be hard and tiring.
Don't expect it to go swimmingly, in some circumstances it can take weeks for things to settle down, and then just when you think you've cracked it a growth spurt will kick in and things start to go haywire again.
It's very very fulfilling but it's not always easy.
From a professional angle, mothers are discharged after a few BF's have been observed and midwives feel everything is ok bit that's not to say things will go well over the next few days. I work on an infants ward and we get lots of BF babies being admitted to us between 3-5 days old as they are losing weight.
The thing with breast feeding is that it's so individual and whereas one person may sail through it another person may encounter problem after problem.
My colleague told me the other day that if she was ever going to BF she would set herself a time limit of three weeks and if things weren't going easily by the end of that time frame then she'd just swap to formula. I told her she was setting herself up to fail if she thought there were 'rules' about BF'ing that she expected her baby to follow.
It wasn't until my DS hit 8-9 weeks that the difficulties and worries settled down.
Bit like I said, other women have no problems and from day one their breast feeding journey is a wonderful one,
My advice is take it one day at a time, don't have any expectations as to how BF 'should be' and seek advice and support whenever you feel like you are struggling.
Congratulations on your pregnancy 