Set up Find My on your iPhone, iPad, iPod touch, or Mac - Apple Support
The instructions to enable Location Services apply to the iPhone:
"If you want to be able to find your lost device on a map, make sure that Location Services is turned on. To do this, go to Settings > Privacy > Location Services, and turn on Location Services."
Do that on your iPhone.
Then, you will be able use your Mac (or even a friend's device) to find your iPhone. Read the three bullet points under Learn more.
You can also set up Find My for your Mac, but that is intended to help locate a lost Mac from some other device. Those instructions are described under How to turn on Find My for your Mac.