There is no good or bad time to have sex for the first time. You have the right to decide when you have sex for the first time.
It is normal for you to feel a bit anxious and insecure about having sex for the first time. Everybody has these feelings. If these feelings are very strong, you may not be ready for sex. Maybe you should wait a bit longer.
It is important that you give your consent to sex. According to the law there is a minimum age at which people can give consent.
You can also choose when you want to have sex for the first time. For example: before or after marriage. Consider really carefully what you want. The decision is up to you. Do not let anyone push you. You can only enjoy sex when both of you are ready for it. Your partner has to respect your choice. Talk with your partner about what you want and how you feel.
You should give your consent and feel ready not only the first time, but every time you have sex.