Question: How to record face (from camera) and screen (from laptop) and keep in sync?

Hello!

Video editing newbie here. I'm trying to record an online course. For that, I'm trying to record my face through my phone camera (explaining concepts) and record my laptop screen (showing running code) at the same time.

Should I record audio on both computer and phone camera, and later on sync them?

How can I superimpose video of me talking on top of the laptop screen recording? Using iMovie / Final Cut Pro X?