This is the easiest method and is recommended for all new bloggers. First of all, install and activate Really Simple SSL plugin on your site.
This plugin fix all your website SSL issues:
- Checks the SSL certificate.
- Sets up a redirect from HTTP to HTTPS.
- Finds HTTP URLs in your content and tries to fix them.
After activating the plugin, click on Settings -> SSL. After that click on Go ahead, activate SSL. This will automatically detect the SSL certificate installed on your site and redirect all your HTTP URLs to HTTPS.