Seems that she is apprehensive in allowing anything in her vagina. She is probably afraid about the pain.
One principle of sex is that dry touching to the woman's genital organs is very uncomfortable and almost always painful. Hence avoid touching her private parts dry. Do not try to entre her vagina till she becomes wet by her secretions. I would rather advice you to enter the vagina only when she demands.
Initially try to spend sufficient (for her) time in body play. Fondle her breasts and gradually go to the nipples. Kissing is a very good starter.
Remember, every day the erotic point on the woman's body changes. You have to find it out yourself during the body play.
Fingering is a good practice in early days. By that you are gradually stretching the vaginal canal and also giving her a confidence that sex is not painful.
In the initial few months to year, full insertion of the penis is not possible. Do not get disheartened. Respect her feelings and empathize her discomforts.
Use of lubricants is always helpful. Please do not use oil-based lubricants as they are harmful to the women's genital organs and condom also. Always use water-based lubricants. Vaginal jellies available across the counter are very good for this purpose. Use lubricants even while fingering also.
I am sure with these few tips you will have a successful intercourse. Do not get disturbed. Time and lubricants are the keys in sexual enjoyment. Intercourse is not only an act, it is an art. Respecting each others sentiments, emotions and feelings are the tools of this art.
So cheer up, go ahead and enjoy your sexual life. I am confident, one day, not very far, you will write to me a direct question telling me how successfully you enjoyed your sex.