Once SSL has been installed on your domain you can auto install WordPress using Softaculous in cPanel using your SSL domain.
You can still install WordPress before the SSL installed but you will need to update the WordPress settings later to use SSL once the SSL certificate has been installed as outlined in the instructions below.
Add SSL to an existing WordPress Installation
Go to your WordPress Admin Dashboard➜Settings page and update the WordPress Address (URL) and Site Address (URL) to include “s” in the url eg. https://mydomain.com.au
Any links or images you have added into the page content may also need to be manually updated to include the “s”.