Does Mohave screen mirroring with an iphone

If you want to see your iPhone on your Mac, you plug your iPhone into the Mac via a USB-to-Lightening cable (you got one with your iPhone).

Then launch Applications -> QuickTime Player

Select QuickTime Player -> File -> New Movie Recording

Click on the little down v next to the record button to select the input source

do you want to mirror from the iphone to the laptop?

if so you have to buy and install airserver on the computer. You can run a free trial for 30 days. More info here: https://www.airserver.com/buy

Note: If you are asking about Sidecar, that is for specific model iPads.

But if Sidecar functionality is what you are looking for, then as Awesomeness111 suggests, you need a 3rd party app