Losing it

This depends on a lot of things.... how much you have done other things before that would have loosened you up a little, how lubricated it is when you have sex for the first time, and also how gentle the guy is.  It doesn't have to hurt really at all.  If it's the right person and you're old enough, it's a very special thing.  Just be careful and don't forget about the condom.  Regrets later are never fun.

Most likely you won't reach an orgasm on your first intercourse practice. I can share from my own experience that it will feel strange at first but you will find the joy in it quickly. I didn't even bleed , my doctors told me it's because i was an gymnastics-athlete for a long time and I probably  popped my cherry stretching  my legs.

too many factors to give an exact answer.  make sure you are well lubricated.

I had a very cool first boyfriend that I could trust, it was both our first time and we spend a lot of time enjoying sexual acts without penetration, so eventually when penetration came, I was already used to being relaxed in a sexual situation and we both enjoyed it very much and it didn't hurt at all.