Apple by default set the hostname of your machine in the <name>-<machine-type> format. For example, it could be Myname-MacBook-Pro. You can change the hostname both via System Preferences and the Terminal.

1. Open System Preferences from the Apple menu.
2. Open Sharing preferences by clicking on the Sharing icon.
3. Change the current hostname to your desired hostname at the Computer Name field.

1. Open Terminal via Spotlight.
2. Set new hostname via scutil using sudo.

   $ sudo scutil --set HostName newhostname