CentOS

Dear All

Im total dummy in centOS.
Use Centos 6.8. Buy cert on https://www.ssl.com/.
Create command curl and download zip with cert.
Where copy this, in or /etc/pki/tls/certs
How Can I add this to my server ? some links manual.

Thanx all,

I see they have support. You may be best off asking them. For example, with your current description, we'd have to guess at the answers.
Generally, on apache, you create a key, generate a csr, give it to the cert company and get a cert. You then have to put that cert and key somewhere, and sometimes an intermediate cert, depending upon where you get it, and reference it in a configuration file.

You may be best off using that company's support services.