As you're likely aware, Google has been gradually pushing web site owners to put their sites under the SSL - aka Secure Sockets Layer - protocol. Starting in July 2018, Google will roll out their latest and most comprehensive non-secure warning. This will no longer apply only to pages with password or credit card inputs. Any site that does not have a secure certificate covering the entire site will display a prominent 'Not Secure' warn to visitors using Chrome.
Since you don't want that on your Site - and since Google will give a ranking edge to sites with secure certificates - if you don't have a cert as yet, now is the time.
You can usually acquire a certificate through your host. GoDaddy, Bluehost, Liquid Web, Siteground, TierPoint and many other hosts expose a certificate order process accessible via your Control Panel or other Client Login interface.
If that is not an option for you - or if you prefer a more well known certificate then the generic ones sometimes offered by hosts - you can acquire a certificate directly from a Certificate Authority. Be aware that this takes a bit more technical knowledge. Here's an overview from SSL Shopper: https://www.sslshopper.com/how-to-order-an-ssl-certificate.html
If you are up for that, then Digicert - which recently purchased Geotrust - is a good place to start: https://www.digicert.com
The Coho Team