Arch Linux installed but cannot login

[Kyle]

The beginner's guide gives instructions that may be a bit too detailed.
I usually go by the installation guide.
https://wiki.archlinux.org/index.php/Installation_Guide
as it seems to be a bit more brief, but still contains all the stuff you
need to do to get a working system.

That said, I think you have done enough to get started. Since you
created a root password, you should be able to login as root using the
password you created in the chroot. From this point, you will add your
regular user, for example

useradd -m -g users -G wheel <username>

as per the example given in the user management section of the users and
groups wiki page.
https://wiki.archlinux.org/index.php/Users_and_Groups#User_management

It may be necessary to set a hostname on your system, even if you aren't
using networking. Pretty much anything will do here.

echo arch > /etc/hostname

If you are having trouble doing that from the installed system, boot
back into the live environment, remount your partitions and do it from
within the arch-chroot. Also, if you plan to install any signed
packages, you will need to maintain something close to the correct time,
although you can set the time manually using the date command if you
don't want to do anything from the internet. Hope this helps.
~Kyle
http://kyle.tk/
-- 
"Kyle? ... She calls her cake, Kyle?"
Out of This World, season 2 episode 21 - "The Amazing Evie"