To install Cordova, follow the instructions for the CLI.
When you try to build, if you get a complaint on Macs that ANT is missing, follow these instructions, and in particular do:
ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"
brew install ant
When you create an app as described in the CLI, do not try to compile it from Eclipse. Use the Cordova commands:
cordova build android
cordova run android
or if you don't have an android device,
cordova emulate android
after you install the emulator. Other platforms work in a similar way.