The most important thing you want to know is, Sex is not like masturbation, you need a partner.
If you can't think about how sex can help you and your partner grow and be happy, you're not ready for sex.
Masturbating with your partner's body will hurt your partner.
Sex can result in sexually transmitted diseases, pregnancy, and even domestic violence.
Do you think you are ready to handle those things?
Even adults can make mistakes, so I recon it's not just a matter of age, depends on how ready you are for the potential events in the furutre.