What should be noted the first time having sex? How to insert correctly?

Patient's question:

| Female
What should be noted during the first time? How to insert correctly?
First question supplement: How many openings does a woman's lower body have? Which one should be entered? Which is the correct vagina?

Doctor's answer:

The first sexual experience is often seen as a sign of maturity, a step in the transition from girl to woman, and a milestone in life. It can mark your status among peers, and it might also be a way to rebel against your parents or a reward for a loyal partner. In reality, however, we still consider losing one's virginity to be a way of closely bonding with a partner. It is a sign that love has reached its highest level. Many women say they feel mentally disappointed after losing their virginity; sexual desire feels more urgent than love; they don't feel like a grown woman, yet they experience a sense of guilt. However, most women are able to continue enjoying a happy sexual relationship—key to building a fulfilling sex life is mutual trust between partners reaching a consensus.
Practical Tips
Ensure your partner understands your feelings about having your first sexual experience; if possible, talk to him beforehand about your concerns. Make proper arrangements for yourself, including a private place and ample time. Contraception is the secret to ensuring you don’t get pregnant from your first sexual experience. If you’ve never used a tampon, your vagina will be tighter. You can insert one finger first, then a second, and a third, pressing downward to widen the vaginal opening. Choose a position that makes it easy for him to enter. Spread your legs, and if possible, place a pillow under your hips. You can apply saliva or KY gel to his penis. Gently guide his penis into position and help him insert it; this will help you feel more in control and in charge of the rhythm. When entering, gently push him slightly downward to avoid tightening your vaginal muscles. Not reaching orgasm the first time—this is just practice.
The hymen is a fold of skin at the vaginal opening, found only in humans and horses, and it lacks real biological significance. If a woman is born with a closed hymen, the hymen needs to be cut open during her first menstrual period to allow blood to flow.