Here are some things that should be true before you have sex. These are important whether or not you've had sex before.
a. I've thought about it outside of the 'heat of the moment' and decided I'm ready
b. I've talked to my partner about my feelings and his/hers, we both feel ready
c. My partner and I have decided on a way to protect ourselves from infection (and pregnancy if that is an unwanted risk for you), we know how to use it
d. My partner and I have talked about the risks of sexually transmitted infections (and pregnancy if that is an unwanted risk for you), we could cope with it if it happened
e. I've thought about my relationship with my partner, our relationship has the level of trust and commitment I need to feel good about sex
f. I feel I could say no to my partner if I wanted to
g. I feel comfortable with this decision; I don't have nagging doubts that I can't explain
If you've talked to your partner and all of these statements seem true to both of you, you may be ready to have sex. Or you may think about all these things and decide it is not the right time. Either way is OK.