I have run through the setup as provided here :
It seems like you don't have Solana installed locally on your machine.
Follow these steps to install: https://docs.solana.com/cli/install-solana-cli-tools#use-solanas-install-tool
Run this command in your terminal:
sh -c "$(curl -sSfL https://release.solana.com/stable/install)"
Alternatively, you can use the Solana playground which allows you to quickly develop, deploy and test Solana programs from the browser.