macOS comes with Python so there's a chance pip is already installed on your machine.
$ curl https://bootstrap.pypa.io/get-pip.py > get-pip.py
$ sudo python get-pip.py
To verify pip is installed properly run
$ pip --version
If it returns a version pip was successfully installed.
Here are a few pip commands to get you started.
Install a Python package
$ pip install <package>
Upgrade a package
$ pip install --upgrade <package>
See what's installed
$ pip freeze
Uninstall a package
$ pip uninstall <package>