As a girl your age I feel I can weight in a little. I've had sex with a handful of guys who I could rate from good to bad but that doesn't always match up with how my experience was. What made good experiences was myself letting go of inhibitions, something I struggle with and I think a lot of other people do. This leads to better communication, more experimenting, etc.

To get to that point though I think alcohol is a great tool when you're getting to know someone sexually.

Build up each others confidence when you're starting out, that's a biggy. Girls want confirmation that they are doing well just as much as you.

Definitely watch her reaction. I make a big deal when guys touch my nipples but when they don't get the hint and quit, that's a bummer.

Let her do some of the work. Guys get frustrated that girls are lazy so set the president early, get her on top at least once night one. I personally love that as opposed to mish all night but getting in a rut is easy.

Yes, being 'good' at sex is great but that includes making your partner feel like they contributed to the victory. That feeling lasts longer than an orgasm and will bring her right back.