To access your WHM, direct your browser to http://SERVER_AIP_ADDRESS:2086 such as http://123.123.123.1:2086
or to access the secure version (preferred) use :
https://SERVER_AIP_ADDRESS:2087 such as https://123.123.123.1:2087 . You will get an SSL warning because of the self-signed certificate it uses but rest assured the connection is still secure.
Note: WHM is not available on shared hosting accounts.