First, create a directory where you will run the Teleport application. Teleport will create subdirectories for it's work when being used, and it is best if you create it's own directory where it can live in isolation. A typical location might be ~/teleport/.
Download a release of Teleport and extract it into your Teleport working directory.
You will need to install the dependencies for using and optionally for developing Teleport using Composer.
Within the root of your cloned repository's working directory:
composer install --dev
The documentation assumes you have installed the phar distribution of Teleport. Since you have chosen to install from source, when you see php teleport.phar in the documentation examples you should substitute bin/teleport to run the application instead.
Get started using Teleport by generating a Profile of a local MODX installation.