Npm nodejs yarn install

Assuming you have installed nodejs on your system next thing is installing developer build tools and yarn is a must yarn is a nodejs package manager similar but different to npm which is installed by default immediately you install nodejs

Open a terminal session onto it type
sudo npm install yarn -g

Yarn is going to have a symbolic link in the bin so don't omit sudo or you'll probably get an ugly error if you are not a super user ie root.

lastly -g argument specifies the package should be installed globally