ATutor readme:
To install ATutor, point your web browser to the installation directory where ATutor was extracted, and follow the Installer's instructions.
e.g. http://localhost/ATutor
For full installation instructions see:
https://atutor.github.io/atutor/docs/installation
Installing from a Github Clone (assuming you know Github)
1. Fork ATutor into your own Github account, at:
https://github.com/atutor/ATutor
2. Clone ATutor from the fork you created into the document root of your webserver (for convenience), with:
git clone https://github.com/yourname/ATutor.git
3. Before running the Installer, create an empty config.inc.php file in the ATutor/include/ directory. If you have a command line to work from, while located in the ATutor directory, create the file with: 
touch include/config.inc.php
4. Follow the installation instructions at the link above.
5. Or, follow the instructions given by the ATutor Installer.
GitHub Basics
If you want to contribute to ATutor, a few Git basics will describe how.
See: https://atutor.github.io/atutor/docs/dev_with_github.html
For additional ATutor documentation, see the ATutor Handbook in ATutor, or at the following links:
Administrators
https://atutor.github.io/atutor/handbook/admin.html
Instructors:
https://atutor.github.io/atutor/handbook/instructor.html
Users:
https://atutor.github.io/atutor/handbook/users.html
Have fun, and take it places!
greg