Almost always, the Node.js package manager (npm) CLI should be used to install yarn. Check out my article FreeKB - Node.js - Install Node.js on Linux.

npm install --global yarn

Or, this one liner can be used to install yarn on Linux.

sudo curl -o- -L https://yarnpkg.com/install.sh | bash

And then reload your bash shell so that the yarn CLI is in your $PATH.

source ~/.bashrc