Installing Pharo can be done by downloading from the site, or for a more up-to-date approach, follow the Deep Into Pharo guide:
curl -L https://get.pharo.org | bash ./pharo-ui Pharo.image
If only part of the software is downloaded, possible errors in the second line are:
Pharo cannot locate the sources file named /.../pharo-vm/PharoV30.sources.