Xcode is a free application that can be downloaded from the App Store. Xcode brings the user interface design, coding, testing, and debugging into a unified workflow.
Begin by connecting the device to the Mac and opening Xcode.
Navigate to Window > Devices. In this window you can see the sidebar with the device name and the device information page on the right hand side.
When the device is selected from the sidebar on the left, it will display specific information of the device (and Apple Watch if paired). To look at the real-time logs, you would need to click the upward facing arrow at the bottom left corners of the screen.
The following image shows some examples of what you might see in the real-time logs:
You can save the logs using the icon in the bottom right corner of the window.