Losing my virginity…

I am going to have sex for the first time, and would appreciate some advice from people more experienced than myself. I really want to, and we will be using a condom. I’m ready to do this. But…

What position is best for the first time?

What do you wish you knew before you had sex for the first time?

Anything else that would be potentially useful to me

And how you lost it, if you don’t mind. I’m a tad nervous. Thanks so much!