Connect iPad Air 2 to Macbook
As you mentioned yourself, you can use QuickTime Player in order to view your iPad screen on the Mac in real time. Here's the exact procedure:


Using a USB-to-Lightning cable capable of data transfer, connect the iPad to the Mac.
Unlock the device and opt to Trust This Computer, entering your passcode if needed.
Launch QuickTime Player, then do ^⌘N (Command + Ctrl + N).
After approving access to camera and microphone if requested (as is needed on macOS Mojave and later), click on the small downwards-facing arrow next to the record button.
Choose your device under Camera in the drop-down menu.


You will now see the iPhone within QuickTime Player on your screen. Keep in mind you won't be able to play content with DRM (e.g. iTunes, Netflix etc.) this way.