It seems to be some sort of issue with node installing. The npm stands for node package manager and the Atom text editor is built using node.js (javascript). Without node successfully installing we won’t get npm and then won’t be able to install those Atom packages.
You should be fine continuing through the Alpha course because everything is in Ruby. We will fix your Node installation when you start at App Academy. If you are having any issues getting through this curse though please let me know and we will do a call to get your environment setup correctly.