If it is in some units. The unit will usually hand it in to you. If you want to handle it in person, you should go to the social security bureau where the Fuzhou talent market is located. Bring your ID card and household registration book (household registration certificate) to the social security center, which generally includes old-age insurance and medical insurance. Generally, it is paid according to the minimum payment base, and there may be different payment grades for you to choose from. The details can be confirmed with the hotline of Fuzhou Social Security Center 12333.
As long as you pay 15 years of social security, you can enjoy old-age insurance when you retire. In the meantime, you are allowed to break, continue and make up. If you think you can pay 15 before retirement, I don't think you need to pay social security.