You need to visit your domain using "https://" at the start including the "www." part of your domain. Remember your secure certificate is installed across the domain including "www." 

Therefore to check the SSL has been installed correctly, visit your site using - 

https://www.[DOMAIN] 

Note - https://[DOMAIN] will result in warning message referring to a security certificate mis-match and won't work. 

Similarly don't forget to use https:// not http:// for all your pages that need to be secure, and images and files included within the page make sure they are referenced using https too, otherwise these items will be insecure and result in warnings. 

For details on the installed certificate your internet browser when visiting the secure page/site should display a locked 'padlock' icon in the bottom right corner of the screen - double click this icon to open the properties and display the details of your secure certificate.