To see your site details, go to Site > Site Settings > Site Details.
You can change the name of your site and site URL.
You can change the name of the Site here. If you change the Site Name and click update, it will be shown at the top of the site.
The URL represent your site can be changed from here.
If the new URL you choose is already in our database, you will not be able to use it. In that case, you need to select a different site URL name.
If you use the old Site URL or links using old URL on any of your pages, it will not work after changing it as it's not recognized at that point.