Hi there!
I return with good news.
I wiped the SDcard, started again from the beginning but this time logged in as
root from the start then began the process of making the filesystems etc.
I am pleased to say I was then able to load up and boot into ArchLinux Arm
I am going to try and find a few other older posts with the same question as mine and answer them for other users.
Thanks for your time! Solved!
Edit:
Just to clarify in case anyone is as foolish as I am. I needed to open a terminal, login to root using
$this->bbcode_second_pass_code('', 'sudo -i')
and then start the installation instructions from the beginning again.
It's a shame because I've seen a few comments on YouTube videos and I think maybe one or two Reddit posts with people running into the exact same problem. I guess the instructions are written from a Arch perspective, not a flavour of Arch
(i.e, Manjaro, where a user will be issuing the commands) which in hindsight totally makes sense, but should have been clarified in the instructions.. especially as it tell you to use
root on step 5.
Anyway, thanks for your time.