You may have run the Wordpress site heath page and seen that your site (if not already setup) is not using "SSL" (TLS/HTTPS). This is an easy fix and one that is really recommended. All sites should be running over HTTPS with no exceptions even if your site is just static it's about protecting your users.
Really Simple SSL automatically detects your settings and configures your website to run over https. To keep it lightweight, the options are kept to a minimum. The entire site will move to SSL.
Really simple SSL is a plugin for Wordpress that will manage and make all the changes for you. You can make the changes yourself but if anything goes wrong you cant get back in, where really simple SSL has a guide to get you back in when it fails.
To enable is a one click option and then you are done, just install the plugin and you will be presented at the top of the page to enable the redirect rule and make HTTPS default.
The Google Bonus
Over the last few years Google actually sees the use of HTTP and sites not using TLS certs and HTTPS by default as a bad indication and will lower your ranking.