no console commands works from nowhere

I wanted to install react native + android studio so i followed this guide on how to do that.
https://shift.infinite.red/painless-...x-39e2e4d58d89

Then from nowhere all these commands stopped working

npm list -g | head -n 1

bash: head: command not found
bash: npm: command not found

bash: apt-get: command not found
bash: sudo: command not found

how do i fix this?