I you have a working installation of Python, just refer to this page to install pip (https://stackoverflow.com/questions/17271319/how-do-i-install-pip-on-macos-or-os-x), then do "pip install --user neo" or "sudo pip install neo" to install the package globally or locally.
If you do not have a Python installation ready, the best move for you is probably to have a look at Anaconda, then go back to the pip paragraph once you have installed it.