Toot by Bruce ToewsBruce Toews (mastodon.stickbear.me)

OK the free version is likely Letsencrypt, and you'll be able to do that through Cpanel, or whichever hosting control panel your host uses. This type of install is typically one-click along with entering which domain you want it for. Note that www and straight top level are two different domains. For example, www.example.com and example.com are separate domains.