Can anyone explain how to register?

Serial does not work and it's not attempting
to call home as Little Snitch is not sending up
any notifications when submitting serial.

Don't quite understand the terminal command
when I enter pico /etc/hosts. It opens up a
huge menu display and then I don't even know
where to enter 127.0.0.1 sams.nikonimaging.com
into the lists.

Can anyone offer a more thorough explanation?