You can use SSL certificate with any site, no issue. Site and data on it become the secured due to the SSL service. When there is communication between the web hosting server and your website, for example, contact form that time, the data is used pass safely that is is encrypted form on the server due to SSL.
So there will be no in-between data hack due to SSL certificate. It provides the assurity to the user who is accessing it that the site is safe to access so visitors access it without any hassle. SSL used to provide the green padlock in the web browser which ensures that the site is safe to access.
So it's always recommended that you should have the SSL certificate on your website.