Your localhost will not be publicly available without opening port 80 (default port on which IIS runs). If you were to open the firewall to allow access to port 80, you are making two assumptions:

A. you know your computer is open to hackers.

B. you expect your computer to be available 24/7.

A better approach is to get your website hosted using a hosting provider like GoDaddy or another server that is available 24/7 to run your site.