First time sex, girl?

Do not think yourself as silly, its not.
Do not do anything you do not feel comfortable with. Keep your curiousity and try out what you like and what you do not like.
Do not think it about how to do, just relax and do what is most pleasurable and lustfull to you. It will come all naturally.
I bet you do not think that much when you masturbate. you just do what feels best. thats how you should deal with sex anyway.
Dont feel bad letting the guy work on you. Many guys like that anyway.
Its important to learn to cherish the feeling of being served.
take your time whatever you do, stay hungry for new experiences. let it come naturally, do not force yourself to do anything you arent ready yet.
If your partner is a understanding and loving one, he will listen to your concerns and talk it over and take you for serious.

do not look what pornactors do because they often/sometimes do it just for the camera.
I am sure its often much more work than fun, making a film looking a lusty porn.
Sex isn´t just about what you do or how you do it.
A big part, maybe even the biggest part, is what you feel and how you make your partner feel.
passion, lust, love, even submission, obedience, faith, trust, desire, cravings….