You can login to cPanel by :
http://cpanel.yourdomain.com
http://yourdomain.com:2082
http://yourdomain.com/cpanel
http://yourdomain.com:2083 [ SSL ]
You can login to WHM Panel by :
http://whm.yourdomain.com
http://yourdomain.com:2086
http://yourdomain.com/whm
http://yourdomain.com:2087 [ SSL ]
You can login to WEBMAIL by :
http://yourdomain.com:2095
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You can also replace yourdomain.com with your server IP too for login !