Congratulations! You’ve decided to redesign your website.
But maybe you still have some love for the old site and want to visit it every now and then. You can create an archive site.
Just create a subdomain where you’d like your old site to live. You could call it mygreatoldsite.mysite.com. But any name is fine.
Then go to your hosting company (I use Bluehost) and go the the File Manager. Copy the files from your old site (you can avoid copying any sub-domains) to the archive folder, mygreatoldsite. You can then visit mygreatoldsite.mysite.com whenever you’d like to see your old site. And you can begin building your new site on your main domain.