Within SharePoint 2019 Central Administration, you can choose to delete a site collection. You can select whether to remove the content database and IIS entry as well.
If you choose to do this and then shortly afterward start receiving TLS errors or destination unreachable type issues, it is important to look to IIS first. When this occurs, I’ve found that for some reason, the SSL cert to other sites sometimes becomes unselected. Simply reselecting the SSL cert on the site binding having issues will fix the problem. An IIS reset is required after.