Installing CentOS 7 in VirtualBox - what is "firstboot"?

[clharrison]

I'm following the guidance provided here https://wiki.centos.org/HowTos/Virtuali ... entOSguest for installing CentOS-7-x86_64-DVD-1708 into VirtualBox 5.4.2. The Vbox VM I created was for Linux/RedHat 64-bit and I allocated a 10GB .vdi and 4096MB of memory, but otherwise changed no VBox settings. The installation seemed to run well, but after rebooting I reached a console. I logged in under the admin user I'd defined during install, but here I'm stuck. The HowTo says to perform a firstboot configuration, but doesn't say how (if it happens automatically, it isn't obvious).

The CentOS Documentation https://www.centos.org/docs/ is kind of empty, beyond hyperlinks to earlier releases. Perhaps I should be looking elsewhere?

I'm brand-new to CentOS, having come from Linux Mint. I'd greatly appreciate a clue to help get me up and running.