Hi @jumpingkangaroo,
Your SSL certificate would have to be installed within your Web Hosting Control Panel (i.e. cPanel/Plesk), as opposed to the Really Simple SSL plugin in WordPress itself.
So, the precise installation steps will depend on what type of Control Panel your Hosting Provider uses. Please find our instruction articles for cPanel and Plesk, some of the most commonly seen control panels, attached below:
cPanel: https://really-simple-ssl.com/installing-ssl-on-cpanel/
Plesk: https://really-simple-ssl.com/installing-an-ssl-certificate-on-plesk/
After installing the certificate there, click the Activate SSL button in Really Simple SSL; and the plugin will make the necessary changes in the context of WordPress, for the site to work correctly over HTTPS/SSL.
Kind regards, Jarno
Get cheap SSL of DigiCert SSL from a trusted provider and after that, you need to follow these steps https://www.digicert.com/kb/ssl-certificate-installation.htm
