Hello,
Thank you for question. There are 2 steps to securing your site:
Step 1: Connect over SSL using a Shared SSL (which is included), or purchasing one for your specific domain.
Step 2:Update your software to the new URL, for example the URL will change from: http://example.com
To: https://example.com
Also, as a side note, always make sure your CMS and all Addons/plugins are fully updated.
If you have any further questions, feel free to post them below.
Thank you,
-John-Paul