No one wants either of you to be experiencing anything other than excitement and pleasure, and the first time can and should bring all that. Only do it when it's right for you. This position allows for her to control the angle of penetration with her hips and both of them have hands free to explore one another and make sure the clitoris isn't ignored. Do not just assume that he is an expert. Yeah - the doctor said the same thing: It means you should never skip the foreplay.
Not an appealing prospect but I guess there's no other way around it:
What You Need To Know Before Having Sex For The First Time
It may sound like a yoga position — and it sort of is — but this is also a great variant for beginner sex. You should always take precautions when having sex. First time sex is generally easiest in the missionary position you lying on your back, him on top of you since penetration is more natural in this position and his penis will find its way into your vagina more easily. It is natural to have many questions and feel that you are going to suffer a lot when he penetrates you for the first time. Have him push in a little at a time, and adjust to each push.