Ok, first I am not a troll, feel free to check I post on here way too much 
These are probably really stupid questions, but no one in my life has ever breastfed so it seems I know nothing at all about it.
I see on here people talking about their milk coming in after a few days, what does that actually mean? If the milk doesn't come in before, what does baby eat?
I also see lots of mums saying how painful it is, what actually hurts? The nipple when baby sucks, the whole boob all the time?
And probably the most stupid question, where does the milk actually come out of? I have looked at my nipple, but no discernible hole IYSWIM?
TIA for helping me out