People have sex for a lot of reasons! While having sex can be to have a baby, many people just enjoy having sex! For many, sex can be a fun activity that feels good. Make sure if you are having sex for pleasure, to use protection to protect against STIs and pregnancy!
On the other hand, many people do not have sex for a variety of reasons. Some have religious reasons why they do not have sex, or they wait until marriage. Others just may not want to have sex, or may be asexual (they do not have sexual attraction to anyone).
All of these options are ok! Whether you choose to have sex or not, make sure you are doing what YOU want to do. And make sure you aren't judging others for what they choose to do as well!