Usually web hosting accounts comes with http and https at same and its up to you about which protocol you need. So in that case when server is not forcing web requests to https then if you entered domain without mentioning protocol it will be opened with http (Not Secured)
So you might be facing not secure warning and your customers will be having trust issues with your website. Now you can think about there is no ssl installed on the website! Yes you can do that here are steps to fix that issue.
1. First of all confirm if you are having an ssl on your hosting or not. For this you can check the ssl status inside your hosting panel, in cPanel it can be seen in SSL Status option. Else you can open a website (whynopadlock.com) here you can search your domain and this will tell you status of your SSL. Now if your ssl is not active then you can consult with your hosting provider else proceed to step 2
2. If your ssl is installed on server then open up your wordpress admin panel and install a plugin (Really Simple SSL) after installing click activate ssl button. It will install ssl in wordpress and you might face logout during this install, now you are set to https. Login again and go to the same plugin and enable 301 redirection for your website and click save.
Now your website is converted to https and ssl is activated properly. Every hit coming to http will be redirected to https.
If you are having any confusion then just watch this video and follow the instructions.