Do not be intimidated my dear Pretty. You are a woman now and it is going to get better. I would just like to share an excerpt from a classic, John Cleland's "Fanny Hill" about a young woman who had her own first experience:
"[The] sturdy stallion had now unbutton'd, and produced naked, stiff, and erect, that wonderful machine, which I had never seen before, and which, for the interest my own seat of pleasure began to take furiously in it, I star'd at with all the eyes I had: however, my senses were too much flurried, too much concenter'd in that now burning spot of mine, to observe any thing more than in general the make and turn of that instrument, from which the instinct of nature, yet more than all I had heard of it, now strongly informed me I was to expect that supreme pleasure which she had placed in the meeting of those parts so admirably fitted for each other."
The full title of the book is, "Fanny Hill or memoirs of a woman of pleasure." by John Cleland written in 1749. I think you will enjoy reading it. You can look for it at Bookpoint on the shelf that has "Penguin Classics" that sell for I think 150/= each. It is beautifully written. It discusses the subject without being vulgar. The English is old but it is very readable.
Sex is a beautiful thing. Enjoy every session.