. . . . How do I make my domain secure from http to https . . .
This is usually not required unless the site has sections where a viewer must login or is offering some functions that require encryption from end to end.
However some browsers ie Chrome insist (rightly or wrongly) on intercepting a HTTP site putting up a 'this site is insecure' message.
If your hosting is with Xara Online then see this article on the older forum for Xara products - AFAIK this still applies
If you are using other hosting, check with the provider if they offer HTTPS (SSL).