Does the 2015 Chevy Equinox have push button start?

If You're referring to "push button start" in the sense of having a physical ignition button on the dashboard of the 2015 Chevrolet Equinox, then no, it does not. In no configuration of any model year Equinox (at present, at least) is push button start offered. However, if You're referring to remote start, where You'll need to "push" a "button" on Your key fob, then yes -- the 2015 Chevrolet Equinox comes standard with this feature. To use it, You'll first need to ensure that Your check engine light isn't on -- as a safety feature, GM disables remote start functionality when this happens. Ensure that all of Your doors are locked, and then press and hold the remote start button on Your key fob for a few seconds.