There is no username or password needed to connect to your Hughesnet service ... however,
There is a "passkey" or "passphrase" needed for a wireless device to use your connection if connecting wirelessly through a router.
If you "dump" that info in a device, you will need to access your Routers internal GUI and get that info so it can be entered into the wireless device.
That is a router wireless encryption issue, not a Hughesnet connection issue.
DHCP is one thing,
How to obtain DNS is another:
You do NOT want the Hughes Modem to do DHCP duties ...
You MAY wish to assign DNS service duties to another place.